“Report of the Committee appointed at a Meeting of Inhabitants of Brighton, held at the Old Ship, on Saturday, May 19, 1827:“In pursuance of a Resolution passed at a Meeting held here, on Saturday, the 12th instant, your Committee have inspected Mr. Vallance’s apparatus for the conveyance of passengers and goods by atmospheric pressure; and can bear testimony to the success of it; having been repeatedly conveyed through the cylinder[18]laid down by that gentleman in Devonshire Place.“Your Committee are of opinion, that, in the event of such a method of conveyance being established from one town to another where much traffic exists, the advantages would be incalculable, both as regards the ready transit, and saving of time and expense to the traveller and merchant, as compared with the ordinary mode of conveyance. Your Committee are informed that 75,000 tons of materials are annually imported into Brighton coastways, the greater part of which is landed at Shoreham, and from thence brought into Brighton, at a land carriage varying from 5s.to 8s.4d.per ton: and your Committee having been assured by Mr. Vallance, that by his principle of conveyance, the carriage of all goods from Shoreham might be reduced to a sum not exceeding 3s.per ton, and yet a net annual profit of ten per cent. be returned on the sum expended, are of opinion that if such a communication were established between Brighton and Shoreham, it would materially benefit the inhabitants of both towns; and your Committee feel confident it would receive the most cordial and general support.“Your Committee beg further to report, that the opinions of some of the highest scientific authorities upon the principle of Mr. Vallance’s proposition, have been submitted to them; and they have the satisfaction to state, that these authorities concur in the practicability of the measure to the fullest extent; and the illustration of it which your Committee have examined, appears to be on a scale of sufficient magnitude to demonstrate the truth of such opinions. Should it, therefore, be adopted between the town of Brighton and London, it is impossible to calculate the important and beneficial changes to which it may lead.“Your Committee, in conclusion, think that a successful mode of transit by Mr. Vallance’s apparatus, would be attended with the most important advantages to this great mercantile nation, and deem it entitled, not only to the attentive consideration of the inhabitants of Brighton in particular, but the community at large.“Your Committee, therefore, recommend, that a requisition be addressed to the High Constable, to convene a Meeting of the Inhabitants of Brighton, to take into consideration the best means of furthering so important an object.“(Signed by the Committee).”
“Report of the Committee appointed at a Meeting of Inhabitants of Brighton, held at the Old Ship, on Saturday, May 19, 1827:
“In pursuance of a Resolution passed at a Meeting held here, on Saturday, the 12th instant, your Committee have inspected Mr. Vallance’s apparatus for the conveyance of passengers and goods by atmospheric pressure; and can bear testimony to the success of it; having been repeatedly conveyed through the cylinder[18]laid down by that gentleman in Devonshire Place.
“Your Committee are of opinion, that, in the event of such a method of conveyance being established from one town to another where much traffic exists, the advantages would be incalculable, both as regards the ready transit, and saving of time and expense to the traveller and merchant, as compared with the ordinary mode of conveyance. Your Committee are informed that 75,000 tons of materials are annually imported into Brighton coastways, the greater part of which is landed at Shoreham, and from thence brought into Brighton, at a land carriage varying from 5s.to 8s.4d.per ton: and your Committee having been assured by Mr. Vallance, that by his principle of conveyance, the carriage of all goods from Shoreham might be reduced to a sum not exceeding 3s.per ton, and yet a net annual profit of ten per cent. be returned on the sum expended, are of opinion that if such a communication were established between Brighton and Shoreham, it would materially benefit the inhabitants of both towns; and your Committee feel confident it would receive the most cordial and general support.
“Your Committee beg further to report, that the opinions of some of the highest scientific authorities upon the principle of Mr. Vallance’s proposition, have been submitted to them; and they have the satisfaction to state, that these authorities concur in the practicability of the measure to the fullest extent; and the illustration of it which your Committee have examined, appears to be on a scale of sufficient magnitude to demonstrate the truth of such opinions. Should it, therefore, be adopted between the town of Brighton and London, it is impossible to calculate the important and beneficial changes to which it may lead.
“Your Committee, in conclusion, think that a successful mode of transit by Mr. Vallance’s apparatus, would be attended with the most important advantages to this great mercantile nation, and deem it entitled, not only to the attentive consideration of the inhabitants of Brighton in particular, but the community at large.
“Your Committee, therefore, recommend, that a requisition be addressed to the High Constable, to convene a Meeting of the Inhabitants of Brighton, to take into consideration the best means of furthering so important an object.
“(Signed by the Committee).”
In proof of the above statements, I beg to refer you to the Records and Official Authorities of Brighton.
And, as a summary of the other persons who have witnessed and experienced the effect of this method of conveyance, additional to the parties already mentioned, I beg to submit the following extracts from a Petition which I presented to Parliament on the subject.
“To the Honourable the Commons of the United Kingdom of Great Britain and Ireland in Parliament assembled; the humble Petition of John Vallance, of Brighthelmstone, in the County of Sussex,’“Sheweth,“That your Petitioner hath invented a method of conveyance, by which he can prove that persons may be carried from one place to another very much faster, cheaper, and more safely, in reference to security from personal danger, than can be done on turnpike roads, or railways; and whereby be can also prove that goods may be conveyed for less expense than by canal carriage.“That to shew the public importance of this method of conveyance, your Petitioner hath put it in operation, on a scale capable of carrying twenty persons at once, over a space sufficient to demonstrate its practicability; as hath been proved by His Grace the Duke of Bedford, the Right Honourable the Earl of Lauderdale, the Noble Baron Holland, and Lord William Russell; who, with several other persons of distinction, at one and the same time, rode in, and experienced the effect of it, on the 2nd December, 1826.“That on the 16th May, 1827, a Committee of seven Gentlemen, nominated at a Meeting of Inhabitants of Brighton, also rode in, and experienced the operation of this method of conveyance.“That His Grace the Duke of Rutland, the Right Honourable the Earl of Egremont, one of the honourable members for Yorkshire, one of the honourable members for Lewes, Professor Leslie, and many other gentlemen, have since witnessed and experienced the effect of it.“That it has also been seen by the Honourable Member for Dundalk, by one of the Honourable Members for Essex, for London, for Southwark, for Barnstable, for Callington, for Stafford, for Petersfield, for Bedford, for Cambridge, for Bossiney, and for Weymouth; with other noblemen and gentlemen too numerous to mention.“That the whole of these noble and honourable gentleman whom your petitioner hath mentioned, appeared to be, and it is your Petitioner’s belief,wereconvinced, that this method of conveyance is equally practicable as steam navigation, gas lighting, or locomotive steam-engines; notwithstanding that before they witnessed and experienced the effect of it, they deemed it more absurd and impossible than those now well known triumphs of art were considered twenty years ago.“That the tunnel and other works whereby your Petitioner hath produced this conviction,combine the operation of the largest pneumatic machinery in the world; the air pumps being capable of exhausting above 50,000 cubic feet[20]of air in a minute; and of conveying 100 tons weight over a space equal to the distance between Manchester and Liverpool, in three hours;—while the tunnel is, in point of calibre and strength, equal to the conveyance of the whole 1000 tons of goods daily passing between those places, at one time.“Your Petitioner humbly begs leave further to represent, that the information he hath obtained during five years which he hath devoted to investigations relative to the practicability, cost, and advantages, of putting this method of conveyance into operation between our principal manufacturing towns, the outports, and the metropolis, will enable him to prove that it may be done of cast iron, for an expense which would not exceed what canals cost; while he can also prove, that in addition to combining the trade of the turnpike road with that of the canal, it would admit of goods being carried for less than half what they can be carried for on canals; and passengers in less than half the time, very much less than half the expense, and far more safely with reference to security from personal danger, than can be done on turnpike roads or railways; it being alike impossible to be overturned, to be driven against any thing, or to break down.”
“To the Honourable the Commons of the United Kingdom of Great Britain and Ireland in Parliament assembled; the humble Petition of John Vallance, of Brighthelmstone, in the County of Sussex,’
“Sheweth,
“That your Petitioner hath invented a method of conveyance, by which he can prove that persons may be carried from one place to another very much faster, cheaper, and more safely, in reference to security from personal danger, than can be done on turnpike roads, or railways; and whereby be can also prove that goods may be conveyed for less expense than by canal carriage.
“That to shew the public importance of this method of conveyance, your Petitioner hath put it in operation, on a scale capable of carrying twenty persons at once, over a space sufficient to demonstrate its practicability; as hath been proved by His Grace the Duke of Bedford, the Right Honourable the Earl of Lauderdale, the Noble Baron Holland, and Lord William Russell; who, with several other persons of distinction, at one and the same time, rode in, and experienced the effect of it, on the 2nd December, 1826.
“That on the 16th May, 1827, a Committee of seven Gentlemen, nominated at a Meeting of Inhabitants of Brighton, also rode in, and experienced the operation of this method of conveyance.
“That His Grace the Duke of Rutland, the Right Honourable the Earl of Egremont, one of the honourable members for Yorkshire, one of the honourable members for Lewes, Professor Leslie, and many other gentlemen, have since witnessed and experienced the effect of it.
“That it has also been seen by the Honourable Member for Dundalk, by one of the Honourable Members for Essex, for London, for Southwark, for Barnstable, for Callington, for Stafford, for Petersfield, for Bedford, for Cambridge, for Bossiney, and for Weymouth; with other noblemen and gentlemen too numerous to mention.
“That the whole of these noble and honourable gentleman whom your petitioner hath mentioned, appeared to be, and it is your Petitioner’s belief,wereconvinced, that this method of conveyance is equally practicable as steam navigation, gas lighting, or locomotive steam-engines; notwithstanding that before they witnessed and experienced the effect of it, they deemed it more absurd and impossible than those now well known triumphs of art were considered twenty years ago.
“That the tunnel and other works whereby your Petitioner hath produced this conviction,combine the operation of the largest pneumatic machinery in the world; the air pumps being capable of exhausting above 50,000 cubic feet[20]of air in a minute; and of conveying 100 tons weight over a space equal to the distance between Manchester and Liverpool, in three hours;—while the tunnel is, in point of calibre and strength, equal to the conveyance of the whole 1000 tons of goods daily passing between those places, at one time.
“Your Petitioner humbly begs leave further to represent, that the information he hath obtained during five years which he hath devoted to investigations relative to the practicability, cost, and advantages, of putting this method of conveyance into operation between our principal manufacturing towns, the outports, and the metropolis, will enable him to prove that it may be done of cast iron, for an expense which would not exceed what canals cost; while he can also prove, that in addition to combining the trade of the turnpike road with that of the canal, it would admit of goods being carried for less than half what they can be carried for on canals; and passengers in less than half the time, very much less than half the expense, and far more safely with reference to security from personal danger, than can be done on turnpike roads or railways; it being alike impossible to be overturned, to be driven against any thing, or to break down.”
The last evidence I adduce, is that of a Major of Engineers in the Russian service; whom the late Emperor Alexander, after he visited England, sent over to inspect and report upon our canals and railroads. This officer was directed by the Russian Ambassador to visit Brighton, expressly to inspect my plan; with reference to which he addressed to his government a report, of which he favoured me with the following copy:—
REPORT TO THE RUSSIAN GOVERNMENT.“To His Royal Highness Prince Alexander, Duke of Wirtemburg, Chief of the Corps of Engineers for the Inland Communications of Russia, General of Cavalry, &c. &c.“Your Royal Highness having commanded me to report upon all the inventions of importance that have been brought forward in England of late years, whether such were, or were not named in the instructions I had the honour to receive from your Royal Highness in St. Petersburgh in June 1824,1 beg leave most humbly to submit the following particulars, relative to a proposed mode of conveyance; differing from every existing system, as much as it will surpass them in point of expedition and ultimate economy.“In March, 1825, I was informed that a Mr. Vallance had invented a method of conveyance, by which goods might be forwarded from place to place ten times faster than can now be done; or equal to 100 miles per hour. The apparent absurdity of the proposition, and the undefined explanation then given, induced me to consider the scheme as one of the nefarious and stock-jobbing bubbles of the day; consequently I took no measures to become correctly informed on the subject; particularly as I was about leaving London for an extensive journey in the interior. Recent circumstances have, however, caused me to entertain so different an opinion to that which I then held on the subject, that I can now confidently submit to your Royal Highness an account of a method of conveyance, which will, in my humble opinion, within a few years, operate a change in the conditionof the whole civilized world; and which would be productive of the most important benefits to the Russian Empire.“The theory of this method is stated in the Treatise marked with the letter A. The practice, I have experienced personally: having been conveyed over a space sufficient to demonstrate the practicability of the principle; and although that space was not sufficient to admit of any such velocity being attained as is adverted to in the Treatise, yet there is sufficient evidence of the velocity with which air may be made to move, to satisfy any one, that on a line of proper length, the only limit to the rate at which persons or goods may be conveyed, will be that at which wheels will revolve. I will, however, first advert to the general object of the Treatise, and then comment on those parts of it which I conceive to require further illustration.“Your Royal Highness will perceive, upon a perusal of the treatise, that the general object of the author is to prove,“1. That it is practicable to render air a means by which we may cause a peculiar sort of wheel carriage to convey both passengers and goods ten times faster than horses can draw any vehicle now in use.“2. That this may be done with perfect safety and convenience.“3. That we may, at one and the same time, move a weight exceeding that of 100,000 infantry or 10,000 cavalry; and, consequently, that a whole army may, in an hour, be transported over a space of 100 miles.“4. That this method of transmission may be put in practice, for an expense per mile, far less than what several canals have cost, as will be apparent from the amounts of the several inland navigations of the United Kingdom, stated in my Report of January last.“5. That the expense of transport by it will be so many times less than by any present method, that military as well as commercial benefits will result from it of the most important nature; and“6. That the stoppages, inconveniences, and delays, which would otherwise arise from those who have charge of the exhausting apparatus at each end of the line of transit, setting it in operation at an improper time, may be prevented by the new mode of telegraphic communication described in the last section of the Treatise, which, being equally efficient during the most foggy weather and darkness, as in day light and clear weather, will admit of instantaneous communication between those who direct the operations at each end; so that any thing which it may be necessary should be known at one end, may be instantaneously communicated from the other, independent of the method of conveyance itself; an arrangement, without which, the operation of the principle would ever be attended with doubt, delay, and danger.“The vast importance which a method of transmission, combining the advantages of tenfold expedition and cheapness, must be, to an empire so extensive as that of Russia, I will not presume to point out to your Royal Highness, but pass to those particulars which appear to me to require further elucidation than the author’s object allowed of his giving.“The first thing is, the velocity at which the cause of motion, in this method of transmission, viz. the air, would move us, provided we could construct wheel carriages to go so fast. This velocity would, if raised to its maximum, be between 900 and 1000 miles an hour. But as saving nine-tenths the time now wasted in travelling post, would render the saving of portions of the remaining tenth, very unimportant, it will be unnecessary to trouble your Royal Highness withproof that it might be possible to do so, in perhaps a large proportion; and I therefore pass to the adduction of evidence, which shows thatit is certainly in our power to save nine-tenths.“From the examination I have given to the construction, and what I have experienced as to the effect of the cylinder, or large tube, in which I was conveyed, according to this principle of transmission, I am convinced that exhaustion, to a degree which should give fifteen inches of mercury, may be effected—that is, half a vacuum; and as this would give an initial velocity of between 200 and 300 miles an hour, there is no reason to doubt but that a rate of motion equal to 100 miles an hour may be attained, provided wheels can revolve so fast without igniting. The operations of nature frequently impart to air a velocity of above 100 miles an hour; and in the process of fusing iron, it is artificially caused to move at rates varying from 200 to nearly 700 miles an hour. At the lower rate of 100 miles an hour, it must therefore be fully practicable to make it move.“The second thing I advert to, is, the quantity in which air may be exhausted, or taken out of a cylinder, or line of large pipe, such as is adverted to. The blast cylinders used instead of bellows, for fusing iron, are all air pumps, and it is requisite only to arrange the valves properly, to render them condensing or exhausting pumps at pleasure. Many of these pumps are large enough to exhaust 10,000 cubic feet of air per minute. Assuming the area of the cylinder to be 100 square feet,[22a]and the velocity at which we are to be conveyed to be 100 miles an hour, the combined operation of eighty-eight of these pumps would be required. But the one referred to in page 18, will take out 22,000 cubic feet per minute; therefore, only forty such pumps as that would be required to exhaust air from the cylinder at the rate of 100 miles an hour—a number, the operation of which there will be no difficulty in combining.“The pressure requisite to cause air to move at the rate of 100 miles an hour, appears, by all experiments that have been made on the subject, to be less than half a pound per square inch. Calculating from this datum the power requisite to move a column of air equal to the area of the cylinder, at the rate of 100 miles an hour, would be that of 1900 horses.[22b]“A steam engine of fifty horses’ power would, therefore, be required to each air pump, to cause the air to move at the rate of 100 miles an hour, independent both of the load to be moved, and of the friction of the air against the inside of the cylinder. With reference to the first of these—the load to be moved—it is to be observed, that, owing to the principle combining the operation of by far the best railway I have ever seen, or, indeed, can conceive, with carriage wheels six times as high as those used on the patent single line railway, friction is diminished to a degree which will admit of the same power moving a considerably greater weight than on that railway. It will, therefore, be quite safe to calculate only on the same effect being produced; and, according to this the extra power requisite to move 100 tons at the rate of 100 miles an hour, would be only 200 horses. With reference to the friction of the air against the inside of the cylinder, as referred to at pages 68 to 74, several times the power will be required; so that, were there no other means of power and exhaustion than steam engines and air pumps, objection might arise in point of expense. But, by what is stated at pages 50 and 51, it appears that neither air pumps nor steam engineswould be indispensably necessary; and although Mr. Vallance does not at present deem it prudent to give full explanation on this particular, he informs me, that whenever it may be requisite, he is prepared to prove that every purpose of exhaustion may be effected without other apparatus than what he can construct out of rough hewn trunks of trees; so that the question may be considered free from any objections which the necessity for costly machinery would give rise to in Russia.“Thirdly, that a vehicle capable of carrying both passengers and goods, can be so adapted to the inside of the cylinder as to be moved in it by the air when operated upon by the air pump, I can vouch, from having seen and experienced it; and as the rate at which this vehicle moves, is exactly commensurate with that at which the pumps exhaust air from the cylinder, it follows, that, at whatever rate air can be pumped out of the cylinder, the vehicle will be carried forward, provided that velocity does not exceed the rate at which wheels can revolve on their axes without ignition: with reference to which, it is to be observed,“Fourthly, that the number of revolutions made by a carriage wheel depends on the size of that wheel, as well as on the motion of the vehicle. The fore wheels of the coaches which travel with the greatest expedition, revolve, on an average, about 100 times in a minute. One of the peculiar advantages of the method Mr. Vallance proposes, is, that it admits of the wheels of the vehicles which move in the cylinder being several times larger than the wheels of carriages which run on roads; owing to their being always kept in an exactly perpendicular position, and consequently free from the strain thrown on the spokes of a common carriage wheel, by the deflections from the perpendicular, which the nature of and obstructions upon roads continually occasion. Owing to this, the wheels of the vehicles which move in the proposed cylinder may be from ten to twelve feet in diameter; or nearly four times as large as the fore wheels of a coach. The same number of revolutions, therefore, which the fore wheel of a coach makes in an hour, would move the vehicle in the cylinder forty miles; and twice and a half that number of revolutions would give 100 miles an hour. Now if a common coach wheel which moves under the disadvantages of being constantly exposed to all the clogging and impediments arising from the dust and dirt of the road, can revolve for hours together at the rate of 100 times a minute, without being greased, excepting at the end of its journey of perhaps one hundred miles, it may fairly be presumed, that a wheel which would be not only free from all dust and dirt, but also moving in a reservoir of oil would revolve 250 times a minute without heating, even had we no such evidence as that referred to in page 36. But when that is taken into the consideration, all anxiety with reference to the effect a velocity of 100 miles an hour would have on the axes of the wheels, may be dismissed.“Fifthly, nor is it necessary that any anxiety should be entertained, as to the effect such a velocity would have on respiration; for in addition to what is urged on this matter at pages 28, 29, and 35, I have to state that, though I was purposely exposed to the ‘vacuum’ as it is termed, many times during my examination of, and riding in the cylinder, yet I did not experience the least inconvenience from it. Indeed, I should not have been aware of it, had my attention not been directed to it; the degree of exhaustion necessary to move a carriage, not being much more than the ten-thousandth part of a vacuum: a diminution of density, which would not lower the barometer so much as the two-hundredth part of an inch.“Sixthly, a degree of exhaustion, or vacuum, which is not sufficient visibly to affect the barometer, being enough to move the carriage with persons in it, so as for them to experience theeffect, and fully comprehend the operation of the principle, it becomes evident that the idea at first entertained of a perfect vacuum being indispensable, is most erroneous; and the objections which at first present themselves to us, relative to the difficulty of constructing the cylinder—of making the joints air tight, and of so adapting the ends of the vehicle to the cylinder, as should prevent the passage of any important quantity of air, without occasioning great friction, are all seen to exist only in imagination. In the cylinder which Mr. Vallance has in operation at Brighton, there is a space of above an inch in width, purposely left all round between the cylinder and the end of the carriage which forms the piston, against which the air presses to drive the carriage along; yet does not the air which rushes through this crevice (though it is in the whole equal to an aperture of two square feet), prevent the operation of the principle: its sole effect being a loss of a proportion of the power employed to drive the air pumps; a loss which Mr. Vallance intentionally submits to, for the sake of proving that a very large portion of air may rush by the piston end of the carriage, without preventing the effect of the principle.—Vide pages 30 and 31.“Seventhly, nor will the degree to which it may be necessary to exhaust, or, as it may in other words be termed, the degree of ‘vacuum’ required, to move even a very great weight, interpose any insuperable difficulty. In the cylinder at Brighton, a party, consisting of his Grace the Duke of Bedford, the Earl of Lauderdale, Lord Holland, Lord W. Russell, Lady W. Russell, and another lady and gentleman, were all at the same time experiencing the operation of the principle, on the day I was last at Brighton, with a degree of exhaustion not exceeding two drachms per square inch; a proportion of vacuum which would lower the barometer about one-hundredth of an inch. Practice therefore proves, as well as the arguments in pages 47 and 48, that a very trivial degree of exhaustion will be sufficient to move a considerable load; and as it will be perfectly practicable to exhaust to a degree, that should render a barometer exposed to the vacuum inside the cylinder, several, if not many inches lower than one would stand exposed to the atmosphere, I do not think the amount stated in page 37 more than it may be possible to move at one time. And with reference to weights of 50 or 100 tons, such as locomotive engines draw at once, there will certainly be no difficulty at all, let the velocity they are moved at be what it may.“Eighthly, under the trivial degree of exhaustion which will thus, generally speaking, be necessary, your Royal Highness will perceive, that rendering the cylinder sufficiently air-tight for the purpose, will be far less difficult than it is at first supposed. Indeed, I see so many different ways of doing it, that I am satisfied it would not, in practice, prove more difficult, nor indeed so difficult, as causing some canals I have seen, to retain the water let into them.—Vide p. 45.“Ninthly, nor will there be any difficulty in regulating the motion of, and stopping the vehicle. The shortest way of rendering this evident to your Royal Highness, will be to suppose the end of the carriage which, when in motion, stands across the cylinder, at a right angle with its course, to be capable of turning on a pivot; so that it may be moved one quarter of a circle, and placed in a line with the course of the cylinder: or edge to wind, like a sail when it shivers. The consequence of this would be, that as the air would pass by without pressing against it, the power which moved the carriage forward would be taken off; and as the wheel could at the same time be dragged by a friction lever, while other levers caused friction against the side of the cylinder, the progress of the carriage could be commanded and stopped at pleasure. This method of removing the effect of the pressure of the air against the carriage, not being that which would be made use of in practice, myreason for adverting to it, is solely to enable your Royal Highness to perceive, that a very simple arrangement will admit of its being done. For the same reason, I only state, that to the axis of each carriage, would be connected clock work, which would shew the person who has charge of the carriage how far he has gone, and where he is, to a yard; so that there will be no uncertainty as to when and where to prepare for stopping, by gradually diminishing the motion of the carriage. There will be every facility for perfect vision, as at each end of every carriage will be fixed a portable gas light.“Tenthly, this principle possesses an advantage over common roads, as well as rail-roads and canals, which will, under all circumstances, be generally, and, in some cases, highly important. This advantage is, that the cause of motion (the atmospheric pressure) will act vertically as well as horizontally; and that in consequence of it, the filling up of hollows, and also deep cutting, as for canals and rail-roads, is unnecessary. Not that it would be advisable to select hilly ground; though perfectly possible to go over any, the most abrupt rises, even were they nearly perpendicular. But that any rise or fall over which a carriage road can be cut, would be quite level enough for the operation of the principle.“Eleventhly, I now mention the expense per mile, which I think will not, in Russia, exceed 10,000l.The calculations on which this opinion is founded, I do not here submit to your Royal Highness; but at such time as may be necessary they will be ready for transmission.“Twelfthly, the expense of transit, or carriage, by this principle. Assuming that the combined effect of the improved railway in the cylinder, and the six-fold diameter of the wheels, should not render any given power capable of moving more than on the single-line railway (vide my Report of August, 1825), one horse would move twenty tons; but independent of the effect which the wheels, being six times larger, would have in diminishing friction, the expense of transmission would be diminished many times, from the following circumstances:—On the single-line railway, the power employed is that of horses; and, considering the construction of that railway, and the height the rail must be in some situations above the ground, I do not conceive that locomotive engines can be ever used upon it. Horse-power is twenty-four times as dear as elementary power, employed in the way the Treatise points out. Assuming, therefore, that the friction of the rarified air against the inside of the cylinder, as stated at pages 68 and 74, should increase the power required ten times, still would the expense of carriage be less than by the single line railway, while we should attain the important advantage of being able to transmit 10,000 tons, at any rate between what railways now transmit at, and 100 miles per hour, for an expense which, as relates to power, would be only the twenty-fifth part of a farthing per ton per mile.“But even were the friction of the rarefied air against the inside of the cylinder to increase the power required ten times, as I have supposed, it is not imperative that the expense of transmission must be increased in a similar degree. Owing to its being well-known and universally received, steam is the first mover, or power, Mr. Vallance has referred to. The researches of men of science in England have, however, been for some years directed to means of rendering the gases first movers, instead of steam, under the hope of obtaining an agent, which should serve as a mechanical first mover, without fuel. From the year 1820, the attention of Mr. Vallance has been directed to this subject, with a view of rendering the method of conveyance the Treatise refers to perfect, in the particular of cheapness of transmission; and about two years ago he obtained a patent for afirst mover, which will give ten times the power of steam, without any expense for fuel; the principle of which is stated in the Tract, marked letter B, which I have obtained from him, for the perusal of your Royal Highness. The power therein referred to, proposed to be used instead of steam, would so greatly reduce the expense of transmission, that the cost of power would be ten times less than by the single line rail-road.“It will also be equally superior in point of safety and security from accidents, as it is in point of economy and expedition: it being, as stated in page 81, absolutely impossible to be overturned.“Thus combining expedition exceeding that of posting, with economy equal to that of canal transmission, it must appear that this principle is most importantly advantageous to an empire so vast in its extent as that of Russia, and, consequently, fully authorizes me most strongly to recommend that the Government should immediately contract with Mr. Vallance, to send a practical illustration of the principle, such as he has in operation at Brighton, which, being capable of carrying your Royal Highness, the Members of the Council, and Generals of the Arrondissements, over a space sufficient to demonstrate the practicability of the proposition, will place within command a reply to all objections from ignorant or interested persons.“It has been deemed essentially important to the welfare of Russia to promote internal communication by canals, and immense sums have been expended in cutting them; but owing to the long duration of winter, they are useless during half the year; and so slow is the rate of transmission by them, that, even when in full operation, they can hardly serve to convey goods from one part of the empire to the other, before winter locks them up again. Railways also, owing to the period the snow lays on the ground, and the continual drifting of it which takes place, would be available scarcely more than half the year. But the principle here adverted to, being liable to interruption from neither frost nor snow, and equally effective by night as by day, offers a means of rendering the extremities of the empire contiguous to each other; and will do this at a much less charge than can ever be done by canals, or any other mode of conveyance.“The vast importance of this principle to Russia, both in a military and commercial point of view, it is unnecessary for me to state to your Royal Highness; but I consider the manifold advantages it presents sufficiently demonstrated, to prompt me to recommend its speedy adoption from St. Petersburgh to Tsarsko-selo, the river Volga, Moscow, and the Black Sea.“William Couling, K. V. &c.“London, Dec. 21, 1826.”
REPORT TO THE RUSSIAN GOVERNMENT.
“To His Royal Highness Prince Alexander, Duke of Wirtemburg, Chief of the Corps of Engineers for the Inland Communications of Russia, General of Cavalry, &c. &c.
“Your Royal Highness having commanded me to report upon all the inventions of importance that have been brought forward in England of late years, whether such were, or were not named in the instructions I had the honour to receive from your Royal Highness in St. Petersburgh in June 1824,1 beg leave most humbly to submit the following particulars, relative to a proposed mode of conveyance; differing from every existing system, as much as it will surpass them in point of expedition and ultimate economy.
“In March, 1825, I was informed that a Mr. Vallance had invented a method of conveyance, by which goods might be forwarded from place to place ten times faster than can now be done; or equal to 100 miles per hour. The apparent absurdity of the proposition, and the undefined explanation then given, induced me to consider the scheme as one of the nefarious and stock-jobbing bubbles of the day; consequently I took no measures to become correctly informed on the subject; particularly as I was about leaving London for an extensive journey in the interior. Recent circumstances have, however, caused me to entertain so different an opinion to that which I then held on the subject, that I can now confidently submit to your Royal Highness an account of a method of conveyance, which will, in my humble opinion, within a few years, operate a change in the conditionof the whole civilized world; and which would be productive of the most important benefits to the Russian Empire.
“The theory of this method is stated in the Treatise marked with the letter A. The practice, I have experienced personally: having been conveyed over a space sufficient to demonstrate the practicability of the principle; and although that space was not sufficient to admit of any such velocity being attained as is adverted to in the Treatise, yet there is sufficient evidence of the velocity with which air may be made to move, to satisfy any one, that on a line of proper length, the only limit to the rate at which persons or goods may be conveyed, will be that at which wheels will revolve. I will, however, first advert to the general object of the Treatise, and then comment on those parts of it which I conceive to require further illustration.
“Your Royal Highness will perceive, upon a perusal of the treatise, that the general object of the author is to prove,
“1. That it is practicable to render air a means by which we may cause a peculiar sort of wheel carriage to convey both passengers and goods ten times faster than horses can draw any vehicle now in use.
“2. That this may be done with perfect safety and convenience.
“3. That we may, at one and the same time, move a weight exceeding that of 100,000 infantry or 10,000 cavalry; and, consequently, that a whole army may, in an hour, be transported over a space of 100 miles.
“4. That this method of transmission may be put in practice, for an expense per mile, far less than what several canals have cost, as will be apparent from the amounts of the several inland navigations of the United Kingdom, stated in my Report of January last.
“5. That the expense of transport by it will be so many times less than by any present method, that military as well as commercial benefits will result from it of the most important nature; and
“6. That the stoppages, inconveniences, and delays, which would otherwise arise from those who have charge of the exhausting apparatus at each end of the line of transit, setting it in operation at an improper time, may be prevented by the new mode of telegraphic communication described in the last section of the Treatise, which, being equally efficient during the most foggy weather and darkness, as in day light and clear weather, will admit of instantaneous communication between those who direct the operations at each end; so that any thing which it may be necessary should be known at one end, may be instantaneously communicated from the other, independent of the method of conveyance itself; an arrangement, without which, the operation of the principle would ever be attended with doubt, delay, and danger.
“The vast importance which a method of transmission, combining the advantages of tenfold expedition and cheapness, must be, to an empire so extensive as that of Russia, I will not presume to point out to your Royal Highness, but pass to those particulars which appear to me to require further elucidation than the author’s object allowed of his giving.
“The first thing is, the velocity at which the cause of motion, in this method of transmission, viz. the air, would move us, provided we could construct wheel carriages to go so fast. This velocity would, if raised to its maximum, be between 900 and 1000 miles an hour. But as saving nine-tenths the time now wasted in travelling post, would render the saving of portions of the remaining tenth, very unimportant, it will be unnecessary to trouble your Royal Highness withproof that it might be possible to do so, in perhaps a large proportion; and I therefore pass to the adduction of evidence, which shows thatit is certainly in our power to save nine-tenths.
“From the examination I have given to the construction, and what I have experienced as to the effect of the cylinder, or large tube, in which I was conveyed, according to this principle of transmission, I am convinced that exhaustion, to a degree which should give fifteen inches of mercury, may be effected—that is, half a vacuum; and as this would give an initial velocity of between 200 and 300 miles an hour, there is no reason to doubt but that a rate of motion equal to 100 miles an hour may be attained, provided wheels can revolve so fast without igniting. The operations of nature frequently impart to air a velocity of above 100 miles an hour; and in the process of fusing iron, it is artificially caused to move at rates varying from 200 to nearly 700 miles an hour. At the lower rate of 100 miles an hour, it must therefore be fully practicable to make it move.
“The second thing I advert to, is, the quantity in which air may be exhausted, or taken out of a cylinder, or line of large pipe, such as is adverted to. The blast cylinders used instead of bellows, for fusing iron, are all air pumps, and it is requisite only to arrange the valves properly, to render them condensing or exhausting pumps at pleasure. Many of these pumps are large enough to exhaust 10,000 cubic feet of air per minute. Assuming the area of the cylinder to be 100 square feet,[22a]and the velocity at which we are to be conveyed to be 100 miles an hour, the combined operation of eighty-eight of these pumps would be required. But the one referred to in page 18, will take out 22,000 cubic feet per minute; therefore, only forty such pumps as that would be required to exhaust air from the cylinder at the rate of 100 miles an hour—a number, the operation of which there will be no difficulty in combining.
“The pressure requisite to cause air to move at the rate of 100 miles an hour, appears, by all experiments that have been made on the subject, to be less than half a pound per square inch. Calculating from this datum the power requisite to move a column of air equal to the area of the cylinder, at the rate of 100 miles an hour, would be that of 1900 horses.[22b]
“A steam engine of fifty horses’ power would, therefore, be required to each air pump, to cause the air to move at the rate of 100 miles an hour, independent both of the load to be moved, and of the friction of the air against the inside of the cylinder. With reference to the first of these—the load to be moved—it is to be observed, that, owing to the principle combining the operation of by far the best railway I have ever seen, or, indeed, can conceive, with carriage wheels six times as high as those used on the patent single line railway, friction is diminished to a degree which will admit of the same power moving a considerably greater weight than on that railway. It will, therefore, be quite safe to calculate only on the same effect being produced; and, according to this the extra power requisite to move 100 tons at the rate of 100 miles an hour, would be only 200 horses. With reference to the friction of the air against the inside of the cylinder, as referred to at pages 68 to 74, several times the power will be required; so that, were there no other means of power and exhaustion than steam engines and air pumps, objection might arise in point of expense. But, by what is stated at pages 50 and 51, it appears that neither air pumps nor steam engineswould be indispensably necessary; and although Mr. Vallance does not at present deem it prudent to give full explanation on this particular, he informs me, that whenever it may be requisite, he is prepared to prove that every purpose of exhaustion may be effected without other apparatus than what he can construct out of rough hewn trunks of trees; so that the question may be considered free from any objections which the necessity for costly machinery would give rise to in Russia.
“Thirdly, that a vehicle capable of carrying both passengers and goods, can be so adapted to the inside of the cylinder as to be moved in it by the air when operated upon by the air pump, I can vouch, from having seen and experienced it; and as the rate at which this vehicle moves, is exactly commensurate with that at which the pumps exhaust air from the cylinder, it follows, that, at whatever rate air can be pumped out of the cylinder, the vehicle will be carried forward, provided that velocity does not exceed the rate at which wheels can revolve on their axes without ignition: with reference to which, it is to be observed,
“Fourthly, that the number of revolutions made by a carriage wheel depends on the size of that wheel, as well as on the motion of the vehicle. The fore wheels of the coaches which travel with the greatest expedition, revolve, on an average, about 100 times in a minute. One of the peculiar advantages of the method Mr. Vallance proposes, is, that it admits of the wheels of the vehicles which move in the cylinder being several times larger than the wheels of carriages which run on roads; owing to their being always kept in an exactly perpendicular position, and consequently free from the strain thrown on the spokes of a common carriage wheel, by the deflections from the perpendicular, which the nature of and obstructions upon roads continually occasion. Owing to this, the wheels of the vehicles which move in the proposed cylinder may be from ten to twelve feet in diameter; or nearly four times as large as the fore wheels of a coach. The same number of revolutions, therefore, which the fore wheel of a coach makes in an hour, would move the vehicle in the cylinder forty miles; and twice and a half that number of revolutions would give 100 miles an hour. Now if a common coach wheel which moves under the disadvantages of being constantly exposed to all the clogging and impediments arising from the dust and dirt of the road, can revolve for hours together at the rate of 100 times a minute, without being greased, excepting at the end of its journey of perhaps one hundred miles, it may fairly be presumed, that a wheel which would be not only free from all dust and dirt, but also moving in a reservoir of oil would revolve 250 times a minute without heating, even had we no such evidence as that referred to in page 36. But when that is taken into the consideration, all anxiety with reference to the effect a velocity of 100 miles an hour would have on the axes of the wheels, may be dismissed.
“Fifthly, nor is it necessary that any anxiety should be entertained, as to the effect such a velocity would have on respiration; for in addition to what is urged on this matter at pages 28, 29, and 35, I have to state that, though I was purposely exposed to the ‘vacuum’ as it is termed, many times during my examination of, and riding in the cylinder, yet I did not experience the least inconvenience from it. Indeed, I should not have been aware of it, had my attention not been directed to it; the degree of exhaustion necessary to move a carriage, not being much more than the ten-thousandth part of a vacuum: a diminution of density, which would not lower the barometer so much as the two-hundredth part of an inch.
“Sixthly, a degree of exhaustion, or vacuum, which is not sufficient visibly to affect the barometer, being enough to move the carriage with persons in it, so as for them to experience theeffect, and fully comprehend the operation of the principle, it becomes evident that the idea at first entertained of a perfect vacuum being indispensable, is most erroneous; and the objections which at first present themselves to us, relative to the difficulty of constructing the cylinder—of making the joints air tight, and of so adapting the ends of the vehicle to the cylinder, as should prevent the passage of any important quantity of air, without occasioning great friction, are all seen to exist only in imagination. In the cylinder which Mr. Vallance has in operation at Brighton, there is a space of above an inch in width, purposely left all round between the cylinder and the end of the carriage which forms the piston, against which the air presses to drive the carriage along; yet does not the air which rushes through this crevice (though it is in the whole equal to an aperture of two square feet), prevent the operation of the principle: its sole effect being a loss of a proportion of the power employed to drive the air pumps; a loss which Mr. Vallance intentionally submits to, for the sake of proving that a very large portion of air may rush by the piston end of the carriage, without preventing the effect of the principle.—Vide pages 30 and 31.
“Seventhly, nor will the degree to which it may be necessary to exhaust, or, as it may in other words be termed, the degree of ‘vacuum’ required, to move even a very great weight, interpose any insuperable difficulty. In the cylinder at Brighton, a party, consisting of his Grace the Duke of Bedford, the Earl of Lauderdale, Lord Holland, Lord W. Russell, Lady W. Russell, and another lady and gentleman, were all at the same time experiencing the operation of the principle, on the day I was last at Brighton, with a degree of exhaustion not exceeding two drachms per square inch; a proportion of vacuum which would lower the barometer about one-hundredth of an inch. Practice therefore proves, as well as the arguments in pages 47 and 48, that a very trivial degree of exhaustion will be sufficient to move a considerable load; and as it will be perfectly practicable to exhaust to a degree, that should render a barometer exposed to the vacuum inside the cylinder, several, if not many inches lower than one would stand exposed to the atmosphere, I do not think the amount stated in page 37 more than it may be possible to move at one time. And with reference to weights of 50 or 100 tons, such as locomotive engines draw at once, there will certainly be no difficulty at all, let the velocity they are moved at be what it may.
“Eighthly, under the trivial degree of exhaustion which will thus, generally speaking, be necessary, your Royal Highness will perceive, that rendering the cylinder sufficiently air-tight for the purpose, will be far less difficult than it is at first supposed. Indeed, I see so many different ways of doing it, that I am satisfied it would not, in practice, prove more difficult, nor indeed so difficult, as causing some canals I have seen, to retain the water let into them.—Vide p. 45.
“Ninthly, nor will there be any difficulty in regulating the motion of, and stopping the vehicle. The shortest way of rendering this evident to your Royal Highness, will be to suppose the end of the carriage which, when in motion, stands across the cylinder, at a right angle with its course, to be capable of turning on a pivot; so that it may be moved one quarter of a circle, and placed in a line with the course of the cylinder: or edge to wind, like a sail when it shivers. The consequence of this would be, that as the air would pass by without pressing against it, the power which moved the carriage forward would be taken off; and as the wheel could at the same time be dragged by a friction lever, while other levers caused friction against the side of the cylinder, the progress of the carriage could be commanded and stopped at pleasure. This method of removing the effect of the pressure of the air against the carriage, not being that which would be made use of in practice, myreason for adverting to it, is solely to enable your Royal Highness to perceive, that a very simple arrangement will admit of its being done. For the same reason, I only state, that to the axis of each carriage, would be connected clock work, which would shew the person who has charge of the carriage how far he has gone, and where he is, to a yard; so that there will be no uncertainty as to when and where to prepare for stopping, by gradually diminishing the motion of the carriage. There will be every facility for perfect vision, as at each end of every carriage will be fixed a portable gas light.
“Tenthly, this principle possesses an advantage over common roads, as well as rail-roads and canals, which will, under all circumstances, be generally, and, in some cases, highly important. This advantage is, that the cause of motion (the atmospheric pressure) will act vertically as well as horizontally; and that in consequence of it, the filling up of hollows, and also deep cutting, as for canals and rail-roads, is unnecessary. Not that it would be advisable to select hilly ground; though perfectly possible to go over any, the most abrupt rises, even were they nearly perpendicular. But that any rise or fall over which a carriage road can be cut, would be quite level enough for the operation of the principle.
“Eleventhly, I now mention the expense per mile, which I think will not, in Russia, exceed 10,000l.The calculations on which this opinion is founded, I do not here submit to your Royal Highness; but at such time as may be necessary they will be ready for transmission.
“Twelfthly, the expense of transit, or carriage, by this principle. Assuming that the combined effect of the improved railway in the cylinder, and the six-fold diameter of the wheels, should not render any given power capable of moving more than on the single-line railway (vide my Report of August, 1825), one horse would move twenty tons; but independent of the effect which the wheels, being six times larger, would have in diminishing friction, the expense of transmission would be diminished many times, from the following circumstances:—On the single-line railway, the power employed is that of horses; and, considering the construction of that railway, and the height the rail must be in some situations above the ground, I do not conceive that locomotive engines can be ever used upon it. Horse-power is twenty-four times as dear as elementary power, employed in the way the Treatise points out. Assuming, therefore, that the friction of the rarified air against the inside of the cylinder, as stated at pages 68 and 74, should increase the power required ten times, still would the expense of carriage be less than by the single line railway, while we should attain the important advantage of being able to transmit 10,000 tons, at any rate between what railways now transmit at, and 100 miles per hour, for an expense which, as relates to power, would be only the twenty-fifth part of a farthing per ton per mile.
“But even were the friction of the rarefied air against the inside of the cylinder to increase the power required ten times, as I have supposed, it is not imperative that the expense of transmission must be increased in a similar degree. Owing to its being well-known and universally received, steam is the first mover, or power, Mr. Vallance has referred to. The researches of men of science in England have, however, been for some years directed to means of rendering the gases first movers, instead of steam, under the hope of obtaining an agent, which should serve as a mechanical first mover, without fuel. From the year 1820, the attention of Mr. Vallance has been directed to this subject, with a view of rendering the method of conveyance the Treatise refers to perfect, in the particular of cheapness of transmission; and about two years ago he obtained a patent for afirst mover, which will give ten times the power of steam, without any expense for fuel; the principle of which is stated in the Tract, marked letter B, which I have obtained from him, for the perusal of your Royal Highness. The power therein referred to, proposed to be used instead of steam, would so greatly reduce the expense of transmission, that the cost of power would be ten times less than by the single line rail-road.
“It will also be equally superior in point of safety and security from accidents, as it is in point of economy and expedition: it being, as stated in page 81, absolutely impossible to be overturned.
“Thus combining expedition exceeding that of posting, with economy equal to that of canal transmission, it must appear that this principle is most importantly advantageous to an empire so vast in its extent as that of Russia, and, consequently, fully authorizes me most strongly to recommend that the Government should immediately contract with Mr. Vallance, to send a practical illustration of the principle, such as he has in operation at Brighton, which, being capable of carrying your Royal Highness, the Members of the Council, and Generals of the Arrondissements, over a space sufficient to demonstrate the practicability of the proposition, will place within command a reply to all objections from ignorant or interested persons.
“It has been deemed essentially important to the welfare of Russia to promote internal communication by canals, and immense sums have been expended in cutting them; but owing to the long duration of winter, they are useless during half the year; and so slow is the rate of transmission by them, that, even when in full operation, they can hardly serve to convey goods from one part of the empire to the other, before winter locks them up again. Railways also, owing to the period the snow lays on the ground, and the continual drifting of it which takes place, would be available scarcely more than half the year. But the principle here adverted to, being liable to interruption from neither frost nor snow, and equally effective by night as by day, offers a means of rendering the extremities of the empire contiguous to each other; and will do this at a much less charge than can ever be done by canals, or any other mode of conveyance.
“The vast importance of this principle to Russia, both in a military and commercial point of view, it is unnecessary for me to state to your Royal Highness; but I consider the manifold advantages it presents sufficiently demonstrated, to prompt me to recommend its speedy adoption from St. Petersburgh to Tsarsko-selo, the river Volga, Moscow, and the Black Sea.
“William Couling, K. V. &c.
“London, Dec. 21, 1826.”
With these evidences that I do not presume to request your attention relative to a mere theory, I trust I may be permitted to hope, that the following observations relative to effecting a communication between your canal at Kensington and the point of termination you propose, may be deemed not wholly undeserving attention.
Were you to purchase land for either a canal or a railway, the width required would not be less than sixty or seventy feet, while in some parts it would be much more on account of the cuttings and embankments.[26]
Supposing the method which I submit to you were to be adopted, a width of only eight feet would be necessary, even were the tunnel to be carried, as a canal or railway must be, along the surface of the ground; so that my proposition has, to recommend it, this first feature, that only one-eighth of the ground would be wanted that must be required for either a canal or railway; while this recommendation would be attended with the additional advantage, that, instead of the tunnel rendering the lands through which it would pass, open, and liable to the depredations of the bargemen and drivers, as canals or railways do, it would, owing to communication going oninsidethe tunnel, leave them still as private, untrenched upon, and uninvaded, as a water or gas pipe would do.
In order, however, still more to obviate objections as to the course, and additionally to reduce expense as to the nature of the ground required for the line of communication which I suggest, I propose carrying the tunnelunderground, in lieu of upon it; while, instead of taking its course across fields and cultivated grounds—as a canal or railway must do—I propose taking it along the line of (though buried underneath) certain bye-roads and (to coin a word) uncultivatible grounds lying between your basin and the Grand Junction Canal, and the line of the London and Birmingham Railway; by doing which, I anticipate that very great expense, and still more important opposition, will be avoided; while, as the farm-roads and tracks, along and underneath which I propose to carry the tunnel, would be so importantly improved by it, as to be rendered almost equal to turnpike roads, the execution of the work would be an actual benefit, instead of an injury to the land under which it was carried.
In addition to these things, the line I propose would save five per cent. on the whole cost; owing to its being in that proportion shorter than the line pointed out on the plan for the railway which was laid before the meeting.
The course I propose is as follows. 1st. Along the road on the east of your basin, to the turnpike road; in which length I should sink it so as to go under the turnpike. 2nd. Diagonally across the turnpike to the bottom of Addison Road; up and underneath which it would be continued to the Uxbridge Road. 3rd. Under that road, and the farm yard and ground opposite Addison Road, to the Green lane which runs upwards by the side of Morland Hall; where would be the onlycultivatedground (and that only two or three furlongs) which it might be necessary to purchase.
From this point it would go under the track to Notting Barn Farm; and from thence under that farm yard up the track to the bridge now crossing the Grand Junction Canal; where I propose obviating any opposition of the Grand Junction company, by fixing the bridge which must be thrown across to carry the tunnel,closeto that bridge; so that there would still be, as it were, but one bridge for their barges to pass under.
From this point it might be carried under the short piece of road leading to the Harrow Road; and thence, under and across that road, up (though under) Kilburn Lane, to the line of the London and Birmingham Railway.
There being only between three and four furlongs, which are cultivatible throughout this route; and as the tunnel (being carried under them) would be no impediment to the usual operations of agriculture (unless some repair should, by chance, be necessary, while the crops were on theground) the expense of the ground line, would, comparatively, be not worth speaking of; instead of proving the costly matter it would be, as relates to a canal or railway.
And the foundation which the width of the “lengths” of the tunnel would give for the railway inside it, being thirty times greater than those of the bases on which the rails of the Liverpool and Manchester Railway are laid (thosebases too, being of an extra and unusual size) the tunnel would be less likely to need repair as relates to its foundation, than the Liverpool and Manchester Railway is, by thirty times. Indeed, owing to the less weight there will be on each “length” of the tunnel, in comparison with that thrown on the railway bases, the probability of repair proving necessary will be less than this.
The stone blocks, or bases, which carry the rails of the Liverpool and Manchester Railway are two feet square. The weight of the large locomotive engines on that railway, is above ten tons; more than half of which, being thrown on two of the wheels, each block has three tons weight on it when those wheels pass over it. The pressure on every square inch of the foundations of the Liverpool and Manchester Railway, is, consequently, above four times as much as on the boilers of Boulton and Watt’s steam-engines; from which result the sinkings, “drivings into the ground,” and the twenty-fold more expensive repairs than were originally calculated on, alluded to in the extract from the Foreign Quarterly Review, given at page11.
Now as the construction of the carriages which would go in the tunnel, would prevent more than three tons being thrown on a “length” of the tunnel; and as each of these “lengths” would expose a base of 120 square feet to the ground, the pressure on each square inch of the foundation of the tunnel, would not be one-thirtieth of what it is on the bases of the Manchester and Liverpool Railway; which, taken in conjunction with the superior bases exposed by the tunnel, would, perhaps, render the probability of sinking less than one hundredth. It may, therefore, be presumed that after the tunnel was once fairly set in its place, it never would be necessary to disturb the ground over it.
Neither will the height to be surmounted by your extension, prove an at all serious impediment to the effect of the principle which the tunnel will enable us to put in operation.
As the pressure of the atmosphere, acting in all directions, admits of a tunnel being effective even were it fixed vertically, all gradations of ascent, fall, necessarily, within in its range; with varieties of effect, increasing in proportion as their angles approach the horizon. In consequence of this, the height to be surmounted in the course of your extension, is merely an impediment of degree; while the following circumstance will render that degree comparatively unimportant.
Few things are better known than that a Stage Coachman, when he approaches a rise of the road, pushes his horses to a gallop; because “the swing of the coach” (as he expresses it) “carries his cattle up the hill.” The principle is known to every one; while it is almost equally well known that the law of its operation, is according to the square of the velocity; so that the momentum of a coach which meets the hill with the horses pushed into a gallop that causes the rate of the vehicle to be 16 miles an hour, will (friction abstracted) rise four times as high as one that meets the hill when going at the rate of 8 miles an hour: the continuance of the operation of the power which overcame friction on the level, being (so far as relates to its counteractive effect) equivalent to an annihilation of friction.
This law is well known. Now let us see how this knowledge has been taken advantage of, by those who have had the expenditure of hundreds of thousands, placed at their discretion.
Rates of from 35 to 40 miles an hour, have been attained on the Liverpool and Manchester Railway for these four years. Supposing friction to be counteracted and neutralized, the momentum of a vehicle that was moving on a level at the rate of 36 miles an hour, would “swing” and cause it to rise up an inclined plane to the height of 43⅓ feet perpendicular, let the angle of ascent, or rate of rise, be what it might; while, as a velocity of 20 miles an hour, would, under similar circumstances, “swing” a carriage up 13⅓ feet perpendicular, and a velocity of 10 miles an hour, 3⅓ feet perpendicular, it needs not,nor ever has neededany thing more than a proper arrangement of levels and inclined planes, to avoidalldeep cutting, high embanking, or tunnelling, in the line of a railway, except where a precipitous rise or hollow interposed itself.
It is true that it may, with reference to the deep cuttings and high embankments of the Liverpool and Manchester Railway be replied, that at the time these works were executed, it was not known that such great velocities could be attained on railways.[29a]But though it was not thenknownthat these rates of motion could be attained, yet was it as well known as it is now, that rates of ten miles an hour could be attained by horses: while, though the first line of the railway was laid out in 1824, and the present line in 1825, it was not till October, 1828, that it became decided whether horse or elementary power should be employed: vide pages 62, 67, 68, and 69 of Mr. Treasurer Booth’s “Account of the Liverpool and Manchester Railway.”
And notwithstanding that instances of velocities equal to ten miles an hour having been attained by locomotive engines, were not very common at the time the line of the Liverpool and Manchester Railway was laid out, yet do the under-quoted extracts from various publications of the period prove, both that theyhadbeen attained, and that much higher velocities were confidently anticipated: while Mr. Treasurer Booth, at page 37 of his book, says, that “the earth work (comprising the cuttings and embankings along the whole line) was not commenced till January, 1827.”[29b]
Such statements being (as it were, officially) promulgated, and such opinions entertained relative to the velocities attainable by locomotive engines:—the question as to the employment of horses being, thus, an open one, not only during the survey for the second line, but also for two years and a half after the Act for the Liverpool and Manchester Railway was obtained; and it being equally well known as it is that the sun gives light, that for the gallop which coachmen push their horses to just before touching a hill, in order to give their vehicles the momentum which imparts the “swing that carries their horses up the hill”, rates of 15 or 16 miles an hour could be attained—it being thus known at the time the line of the Liverpool and Manchester Railway was laid out, that average velocities of 10, and occasional velocities of 15 miles an hour could be attained: and it being unquestionable that if friction be counteracted (as it is by the continuance of the operation of the moving power) the momenta imparted by those velocities will carry any vehicle up any inclined plane to the heights of 3⅓ and 7½ feet, it was necessary only to have laid out the railway in short levels, with sharp inclined planes rising a foot or two between them, to have avoided all deep cutting or high embanking.
It is true that owing to velocities of ten miles an hour, having at that time, been only occasionally attained by locomotive engines, it might have been proper to keep these ranges of levels, and inclined planeswithinthe limit prescribed by that rate. But as this limit is not within a vertical rise of 3 feet 4 inches, it would have been perfectly possible, by arranging short levels with sharp inclined planes of three feet in height between them, to have avoided thewholeof those deep cuttings and high embankments of the Liverpool and Manchester Railway, of which the under-quoted extract from Mr. Treasurer Booth’s book gives such glowing descriptions.[30]
Admitting, however, (for the question’s sake) that the “most eminent engineers” and their“assistants of undoubted talents,” by whom these “Pelion-upon-Ossa-like spoil banks, towering over the adjacent land” were ordered—and of which Mr. Booth says, in addition, “this aggregate mass has been removed to various distances, from a few furlongs to between three and four miles; and no inconsiderable portion of it has been hoisted up by machinery from a depth of 30 to 60 feet”—admitting that these gentlemen should have been warranted in expending the hundreds of thousands which were paid for making these mountains between Liverpool and Manchester, by the uncertainty then prevalent as to what velocities were attainable by locomotive engines, it cannot be said that the engineers of the London and Birmingham Railway have any similar justification to plead. That line was not, I believe, laid out till 1831, while the velocities attained on the Liverpool and Manchester Railway, and the short time within which London and Birmingham could, in consequence, be brought of each other, form the main features of the prospectus: rates of from 35 to 40 miles an hour having been (then)longattained on the Liverpool and Manchester railway.
Yet does the “Estimate” laid before Parliament shew no less a sum than 429,286l.appropriated to “Excavations, Embankments, and Tunnelling,” which, with “the increase in the number of arches in the Wolverton viaduct,” will give anestimatedexpenditure of nearly half a million to do that, which, takingproperadvantage of the law of motion I am adverting to, would entirely have saved; except where a hill as perpendicular as a wall, or a hollow as precipitous as a well, rendered tunnelling, deep cutting, or filling up, absolutely unavoidable.
At the time the Birmingham Railway was before Parliament last session, maps of it wereissued from the office of that company, which gave the “Section of the line of railway; shewing the rises and falls.”
This section is on too small a scale to shew either the height of the embankments or the depth of the cuttings: and though it has not suited my convenience to spare the time necessary for examining the section deposited in Parliament, yet as the cubic yards of cuttings and embankments amount to nearly twenty-three millions: as the map and section I have just mentioned shew ten tunnels (some of which are a mile and upwards in length): and inclined planes, inunbrokenrises of 6, 8, 10, 11, 13, 20, and 25 miles, there can be no doubt but thatmuchdeep cutting and high embanking is included in it. Now though I do not mean to imply that the expense ofallcutting and embanking could have been saved, by taking proper advantage of the power of ascending heights, which is imparted by the momenta of the velocities whereat locomotive engines now go, yet I do mean to state it as my full conviction, that had this railway been (as the second prospectus of the Liverpool and Manchester Railway, stated that line should be) “laid down and arranged with that skill and conformity with the rules of mechanical science, which will equally challenge approbation, whether considered as a national undertaking of great public utility, or as a magnificent specimen of art” the whole of the anticipated expenses ofdeepcutting andhighembanking would have been expunged from the estimates; it being certain, that deep cuttings, high embankments, andlonginclined planes are no more evidences of engineering skill, than winning a battle by hard fighting is of generalship: while the expense of the numerous “very small cuttings varying from 8 to 10 feet,” which are spoken of in the “Minutes of Evidence taken before the Lords’ Committees,” might as certainly have been saved, and those rises passed over by the vehicles in consequence of their momentum; as a cricket ball will roll over a mole-hill.
But if these remarks are applicable to the Birmingham Railway—the line of which, was I believe, laid out in 1831—what must be said relative to thenowproposed London and Bristol Railway?
For nearly twelve months the principle of avoiding level, and constructing “undulating railways” has been discussed, in consequence of Mr. Badnall having taken out a patent for, and published a work, proposing such “undulating railways”: and though, owing to the fall on your line being wholly (as well asgreatly) one way, it is not necessary to express any opinion here on a proposition, which appears to have for its object the construction of unlevel railwaysin preferenceto level ones, and the labour of toiling up hill for the sake of the momentum to be obtained by running down hill, yet as, in consequence of it, the effect of momentum in carrying moving bodies up ascents, has been largely and widely adverted to for the last twelve months (nearly), it must have been within the expectation of every one, that, let the gentleman who has been employed to lay out the line of the Bristol Railway be anxious as he might, to avoid any “undulating” proposition, he would be equally anxious to call in the aid of allknownandestablishedprinciples, to diminish the expense of the line he was required to lay down.[32]
Now, nothing, I believe, is more certain, than that if a vehicle be moving along a level at the rateof 2¾ (2.7272) miles an hour, it will, on coming to an inclined plane, and provided the operation of the power which overcame friction on the level, be continued, so as to neutralise and (as relates to counteractive effect) annihilate friction during the ascent, “swing” itself up, and rise to the height of (that is, its momentum will cause it to rise to the height of) three inches perpendicular; let the angle of ascent, or rate of rise of the plane, be what it may.
Equally certain is it, that if the velocity of the vehicle be twice 2¾ miles an hour, that is 5.4544 miles, the momentum will (under similar circumstances as to counteraction of friction) then cause the vehicle to rise up said inclined plane to four times the height to which the former velocity raised it; or to the height of one foot. And it is equally certain, that the momenta imparted by increased velocities will, under the circumstance of the friction of the vehicle being overcome, neutralised, and (as relates to counteractive effect) annihilated, by the continued operation of the moving power during the ascent, cause the vehicle to rise up any inclined plane to the perpendicular heights stated in the following table:—
Carriages moving on levels, at the under-mentioned velocities, the motions of which are changed from horizontal to ascending, by means, either of circular or angular ascents.
Have momenta, which (friction being counteracted and neutralised) will cause them to rise to the under-mentioned heights (perpendicular) above the level where those velocities were attained: let the rate of rise, or angle of ascent, be what it may.
MILES.
MILES PER HOUR.
PERPENDICULAR.
2¾
or
2.7272
3 inches.
5½
or
5.4544
1.0 foot.
11
or
10.9088
4.0 feet.
22
or
21.8176
16.0 do.
44
or
43.6352
64.0 do.
88
or
87.2704
256.0 do.
176
or
174.5404
1024.0 do.
352[33]
or
349.0808
4096.0 do.
Now, let it have been proper as it may, that the gentleman whose name appears as “Engineer” to the Bristol Railway, should (in laying out that line) have avoided encumbering the subject with the “undulating” question, there can be no doubt that it was incumbent on him to diminish expense in every way whichestablishedprinciples admitted. And as the usual railway rate is now 20 miles an hour, while that rate will give momentum enough to cause any vehicle to rise up any inclined plane to the height of 13⅓ feet (perpendicular) above the level on which it was running at the rate of 20 miles an hour, it is necessary only to lay out the line of this railway in levels, and rises of 10 feet each, to avoid (very nearly, if notquite) all necessity for cutting, or embanking; whiledeepcutting,highembanking, and tunnelling, might (except inverypeculiar cases) have been as certainly avoided, as erecting a suspension bridge will obviate the necessity for piers and arches over a river. Yet does not this gentleman appear to have any more called in the aidof this law of motion, than did those equally “eminentengineers” who laid out the line of the Liverpool and Manchester Railway; or those who have laid out that of the Birmingham Railway: the “Report” of the public meeting held at Bristol, on the 30th July last, stating that “although the line of country (except for about 30 miles at the Bristol end) isvery advantageous, yet the comparative levelness of the railway will be attained by agreat dealof deep cutting, andseveraltunnels;” while the prospectus issued from the London office of the Company states, that “the construction of a road so nearly level, in the hilly country about Bath and Bristol, will, unavoidably, be a costly work.”
The length of the Birmingham Railway is 112½ miles; that of the Bristol Railway “from 115 to 118 or 120 miles,” average 117½. The estimated expense of the cuttings, embankments, and tunnels, of the Birmingham Railway is 429,286l.or 3,185l.per mile. The same expense on the Bristol Railway is (835,300l.+ 15,000l.=) 850,300l.or 7,236l.per mile; that is, above twice as much: and this too, notwithstanding that the Report states that “this expensive part of the work, fortunately, lies principally in two of the most favourable materials—the chalk and the freestone;” and also notwithstanding that the estimate of the Birmingham Railway has undergone two years’ scrutiny, and the most rigid investigation, by several Parliamentary Committees; while that for the Bristol Railway is the result of only a “preliminarysurvey,” directed by a “Provisional Committee:” so that were it to be increased as the estimate for the Birmingham Railway has been increased, it would bemanytimes as much as the similar work on that railway. Indeed, the parties themselves have made a considerable increase already: 10 per cent. being added to the above amount of 850,300 by the Bristol Committee, and 7 per cent. by the London Committee;[34a]so that 978,494l.is thewholeamount at present allowed for works, which taking proper advantage of the momentum of the vehicles would have saved.
Yet, with well-known laws of motion thus set at nought and neglected, and with expense thus unnecessarily as well as most enormously added to, are the Committee—gentlemen who were, unavoidably, as entirely dependant on the opinion of their engineers, as the Ministry of 1789 were upon that of the “Insanity Doctors,” relative to the mental affliction of George III.; or as those of 1830 were on that of the physicians who attended George IV. during his long illness—under circumstances of such entire dependence on the opinion of their engineers, are the “Provisional Committee” of the Bristol Railway led into the following expressions of approbation in their Report: “The Committee think it but justice to say, that the zeal, the diligence, theability and other valuable qualitiesmanifested by these gentlemen, have given them ample reason to congratulate themselves on their choice”!; and “The Committee, in conclusion,repeatthat they have carefully availed themselves of the resources ofskill and experiencein investigating the probable cost of the railway.”[34b]
Now as, were I to presume to manifest “skill, experience, ability, and other valuable qualities,”such as these, with respect to your line, or thus to throw away, not only hundreds of thousands, but also half millions, on any other, I should be sure to experience the truth of that proverb, which says that merely looking over the hedge shall subject one man to the operations of “thefinisherof the law,” while another man may steal the horse with impunity, I must avail myself of this law of motion, which “skill, ability, experience, and other valuable qualities” so neglect and despise, to get loads up the rise which you wish to surmount, without resorting to deep cutting or high embanking.
Sixty feet of the rise to be surmounted, occurring in the last half-mile of your line, I shall have nearly two miles to acquire the necessary velocity in: and as the continuation of the action of the power which overcame friction on the level, will neutralise, and, as relates to counteractive effect, annihilate the friction of the carriages while ascending these sixty feet, I have only to cause them to attain a velocity somewhat greater than has yet been attained on railways, that is, 42½ miles an hour during the two miles, to enable them to “swing” themselves up these sixty feet, in consequence of the momentum which that velocity will impart: while, let the height of Rodway Hill (which is adverted to as so desirable to avoid, in the Report of the Provisional Committee of the Bristol Railway) be what it may, all that would be requisite to obviate the necessity for the “inclined plane and stationary engine” spoken of as unavoidable there, would be to attain the velocity due to the altitude of said hill, to enable my vehicles to surmount it from their momentum.
Nor would the ascending power imparted by the vertical operation of the pressure of the atmosphere, be much less important with respect to diminishing the expense of bridging, on the line of this Bristol Railway, than would “momentum” as relates to the expense of cuttingand embanking. From the map issued from the London office of that Company, it appears that that railway is to be carried five times across the Avon; twice across the Kennet and Avon Canal; three times across the Wilts and Berks Canal; and four times across the Thames. These various crossings are not for the sake of approaching places of magnitude, or commercial importance; but solely because theprincipleof railway transmission compels the level to be servilely adhered to: while, though the right line distance between London and Bristol is only 108 miles, yet is the line of railway there laid down, shewn as being 120 miles long; the 12 additional miles being added by the curves taken in thus crossing these waters for the sake of the level.
Now though I do not mean to say that it would be possible, by laying down a tunnel instead of this railway, to avoid all bridging whatsoever, yet owing to hills and rises being no impediment to the operation of this principle, the line for a tunnel might be several miles shorter than this line of the railway, and yet the whole of these bridges be saved, excepting one over the Avon; while not a quarter of the expense would be incurred for carrying a tunnel over the waters whichitscourse must cross, which will be incurred in bridging the railway over those other waters that intersect its course, which are not laid down in the map shewing its line.
The estimated expense of bridging for the railway is 474,800l.; which, when increased by the per centages allowed by the Committees, amounts to 556,194l.as the wholeestimatedexpense of bridging. What proportion of this amount is for bridging over waters, and what for bridging over roads, is not stated. On the Liverpool and Manchester Railway 108,565l.11s.9d.was expended on 63 bridges; of which only five were over waters: the other 58 being over roads, or to carry roads over the railway. On the Birmingham Railway the number of bridges is 300; of which only nineare statedto be over waters, the others being for roads. The estimated amount of them is 350,574l.One bridge alone (the Sankey viaduct) on the Liverpool and Manchester line, cost nearly 50,000l.
Now as the power of going up or down, imparted by the vertical operation of the pressure of the atmosphere, would render it wholly immaterial whether the level was preserved in the line of a tunnel; as burying it under ground, in the manner proposed at page27, would equally do away with any occasion for themanyhundreds of bridges, which, on the three lines I have mentioned, must be provided to carry those railways clear of roads, as it would save bridging over the roads on your line; and as a tunnel could have been carriedunderthe Sankey, for almost one-tenth of the expense it cost to construct the viaduct by which the Liverpool and Manchester Railway is carried over that canal—as my principle offers facilities of this kind for obviating the necessity of bridging—I do not hesitate to say, that, on the whole three lines, and considering how much the actual, will exceed the estimated amounts, above one million sterling might be saved in the item of bridging alone, by substituting tunnels for railways; which, when added to, as it would be, by the almost equal amount that would be saved in the expense of the land, in consequence of my plan requiring a width of only ten or a dozen feetunderground, instead of from 60 to 300 on the surface, will admit of my saying that (in round numbers) nearly two millions might be saved by my plan, in these two items of bridging and land, on the lines of the Liverpool and Manchester, the London and Birmingham, and the London and Bristol Railways: while, if what my plan would save of the 398,286l.allowed for the cost of land, and of the 261,928l.allowed for that of the entrances to London, Bath, and Bristol, be added to the savings I have stated it would effect inbridging, cutting, embanking, and tunnelling, I may say that it would also save nearly two millions (of thepresentestimated expense) on the Bristol Railway alone.
The ten times greater heights than I have yet specified, which may be surmounted by combining the operation of the momentum of theair itselfwith that of the vehicles, it is not necessary for me to trouble you with, owing to the shortness of your line, and the small height to be ascended: though it may be permitted me to observe, that as attaining only equal velocities to those which have been spoken of as attainable by locomotive engines and steam-coaches, will enable my vehicles, of themselves, to surmount hills of many hundred feet in height; while combining with their momentum, the momentum of the air itself (that which isbeforethe vehicles; the friction whereof will be overcome, and neutralised by the operation of the exhausting apparatus) in tunnels of proper length, and loads of corresponding weight, will enable me to ascend more thousands of feet, than the momentum of the vehicles alone will carry them up hundreds, I may be able to extend Louis le Grand’s exclamation, “Il n’y a plus des Pyrennées,” to “il n’y a plus des montagnes sur la terre,” so far as relates to their longer preventing intercourse between countries; and consequently render the whole earth level to us, in point of effect.
In reference to the force required to overcome the friction of the medium by which the moving power operated to impel the carriages, would a tunnel be also superior to a railway. From Messrs. R. Stephenson and Locke’s reply to Mr. Walker’s Report to the Directors of the Liverpool and Manchester Railway, it appears that the friction of the ropes by which stationary engines draw waggons up inclined planes, is one-twelfth of their weight: while, as the latter part of your line gives a sharper rise than that of the Liverpool tunnel, the weight of the rope you must use should not be less than 7lbs. per yard; the friction and gravitation of which would be 0.73231b. per yard, or 1289lbs. per mile. The line in the plan for the railway, which was laid before your meeting, being 2½ miles long, the whole resistance of friction and gravitation upon it would be 3222 lbs.
From experiments on the friction of air in tubes, I am enabled to state that both the inertia and friction of the air against the inside of an equal length of the tunnel I propose to you to lay down would not, when said air was movedby exhaustion, and conveying 50 tons at the same rate at which the same quantity is drawn up the tunnel of the Liverpool and Manchester Railway (i.e. ten miles an hour), be so much as one sixteenth part of this; while it would have this important advantage, that the heavier the load was, the less would be both the inertia and friction of the air. For instance: the degree of exhaustion requisite to admit of an equal load to what is drawn up the Liverpool tunnel (i.e. 50 tons) being moved up a tunnel of the same size as that I constructed at Brighton, and rising at the same rate your’s must rise (1 in 47) by the pressure of the atmosphere, would be about the 40th part of a vacuum.
But supposing ten times this load were to be raised, the degree of exhaustion must be ten times as great, or about the fourth of a vacuum. And, as the greater the exhaustion, the less the expansive power, and, consequently the less the inertia and friction of the air inside the exhausted part of the tunnel, this “rope of air” as it has, derisively, been called, possesses the important advantage of decreasing as relates to the density, inertia, and friction, whichitselfopposes, in proportion to the increase of the load drawn by it: while, as the valves I should place at every quarter, or half, or whole mile, to be opened by the carriages as they pass them, and admit air immediately behind said carriages, would prevent there being the inertia and friction of more thana few hundred yards of air of thenaturaldensity behind the carriages to be overcome, the impediment which presents an insuperable obstacle in the opinion of the numbers who have condemned the proposition (because they deemed operating by exhaustion the same as operating per plenum) diminishes, in point of fact, to a far less important hindrance, than that which is occasioned by the old system of drawing loads by means of stationary engines and ropes; since, in the present instance, the inertia and friction would not be the one-hundred-and-sixtieth part of what it would be, to move an equal quantity by the stationary engine, and rope system.
And notwithstanding that the superiority which the tunnel possesses over the locomotive system is not so great at this, yet is it important.
In the instructions given to Mr. Walker by the Directors of the Liverpool and Manchester Railway (and which called from him the Report criticised by Messrs. R. Stephenson and Locke), it is stated that “the quantity of traffic for which it will be expedient to provide the power of conveyance” is about 4000 tons, from each to the other of those places, daily.
In his publication on the Liverpool and Manchester Railway, Dr. Lardner says, “In the experiments which I have detailed, it appears that a steam engine is capable of drawing 90 tons at the rate of about 20 miles an hour; and that it could transport that weight twice between Liverpool and Manchester in about three hours.”[38a]The weight of this engine alone being 8.1 tons, the whole weight of itself, and its tender, with the necessary supplies of fuel and water, will not be less than twelve tons. Therefore, the friction of the engines (and their tenders) requisite to carry these 4000 tons at the rate of 20 miles an hour, would be 4267 lbs.
The friction of one mile of air in a tunnel eight feet in diameter, when moved at the rate of 20 miles an hour byexhaustionbeing 288lbs., the friction of it in a tunnel extending from Liverpool to Manchester, will be 8640lbs.: which, though double the friction of these locomotive engines, might be far cheaper for the following reason; and independent of the circumstance, that I could lay down a tunnel capable of carrying all these 4000 tons at one and the same time, from Liverpool to Manchester, for one-fourth of what that railway has cost;[38b]and also independent of the circumstance that the enormous expense now incurred for the repairs of the locomotives (as stated on page11) would also be saved.
It is well known that the smaller a steam-engine is, the larger is the proportionate quantity of fuel it requires, and the greater the proportionate expense of working it; while it is equally well known that, owing to the imperative importance of lightness and efficiency over economy in locomotive engines, this disadvantage increases in a most rapid ratio with respect to them. In consequence of this, a quantity of fuel, which, in large stationary engines, such as I should use for exhausting air from the tunnel, would do a given quantity of work, would, in the best of the locomotives on the Liverpool and Manchester Railway, do only one-sixteenth as much work.
Therefore it results, that, notwithstanding the friction of the air in a tunnel 30 miles long would, at the rate of 20 miles an hour, be twice as much as the friction of the locomotive engines, yet, owing to the fuel consumed by the latter, to move themselves and their tenders, being sixteen times as great as large stationary engines, such as I should use, would require to do the same work, the tunnel would, supposing the whole quantity of goods were to be carried at once, be eight times the cheapest mean of conveyance, in point of current expenses only, and without reference to its first cost being only one-fourth that of the railway; and also without reference to the whole of the enormous expense now occasioned by the repairs of the locomotive engines being saved.
But this is not the only proportion in which a tunnel might be cheaper. The 13th paragraph of the Russian Engineer Officer’s Report, states, that he is “convinced that exhaustion to a degree which should give a pressure of fifteen inches of mercury may be effected in the tunnel.” Now, notwithstanding that much more than this may be done in an iron tunnel, yet will I calculate on this only. Fifteen inches of mercury being 7.3 lbs. that pressure on the area of the tunnel, would move above twice the 4000 tons which the Directors of the Liverpool and Manchester Railway estimated would be carried from one to the other of those places every day; which, supposing that weight to be conveyed at one time, would reduce the expense (per ton of goods carried) of overcoming the friction of air moving in a tunnel from Liverpool to Manchester, at the rate of 20 miles an hour, to one-sixteenth of what the power required to overcome the friction of the locomotive engines required to draw the same weight would cost.
And though, owing to its being a received opinion that the power required to overcome the friction of fluids increases according to the square of the velocity, we are to suppose that at 40 miles an hour, the fuel required to overcome the friction of the air would be one-fourth that of the locomotive engines, while at 80 miles an hour it would be equal to that of the engines, still would a quadruple velocity be attained, by the expenditure of only an equal quantity of fuel.
The amount of the power required to overcome the friction of the locomotive engines (and their tenders) necessary to carry 4000 tons weight from Liverpool to Manchester daily, at the rate of 20 miles an hour, is, when expressed in “horse’ power” equal to the power of 225 horses working for an hour and a half. In other words, these locomotives must exert power to this amount, beyond what is required to draw the 4000 tons weight.
The power required to overcome the friction of air, which was moving (by exhaustion) at the rate of 20 miles an hour, in a tunnel of eight feet diameter, extending from Liverpool to Manchester, would be equal to that of 456 horses: which, though double the preceding, would yet be eight times cheaper, owing to large stationary engines, such as I should use, requiring only one-sixteenth part of the fuel required by locomotives to do equal work.
At 40 miles an hour (supposing locomotives could go so fast) the number of horses’ power required to overcome the friction of the air in the tunnel would (according to the received opinion of that friction increasing to the square of the velocity) be 3650: which, though sixteen times greater than that of the locomotive engines and their tenders, yet, in consequence of this power being exerted only for three-quarters of an hour, instead of an hour and a half, and of fuel doing sixteen times as much work in large stationary engines as in locomotives, would be only half so expensive as the locomotives and their tenders would prove.
At 80 miles an hour (which is twice as fast as locomotives can go) the power requiredto overcome the friction of the air in the tunnel, would (on the calculation that it increases according to the square of the velocity) be equal to that of 29,196 horses; which is nearly 130 times as much as the locomotive engines would require: though, owing to this power operating only 22½ minutes, instead of an hour and a half, and to fuel in large stationary engines doing sixteen times as much work as in locomotives, the expense would be only twice as great as in the locomotives, exclusive of the whole of the most enormous expense now incurred, by the repairs of the locomotives being saved (which would, alone, more than make up the difference) and also exclusive of the tunnel costing only one quarter of what the railway has cost, and of the rate of conveyance being four times as fast.