APPENDIX.

In continuation of this list of “nobodies,” to whom we owe so much of our national greatness, I ask, to whom are we indebted for the very inventions which the engineers of the present day claim as their own, with justice equal to that wherewith the organ-blowerconsidered the tones of the instrumenthis?

Railways have been in use among us for a century and a half; and, notwithstanding that those of this remote date, were no more comparable with those of the present day, than the matchlocks of the same period are with a modern gun, theprinciplewas equally developed in the one case as in the other. Yet is there no engineer who can claim the credit of having said “As this principle admits of most important benefits being conferred on society, provided it be worked out, and carried to the perfection it admits of, I will devote myself to such working out and perfecting.”

Locomotive engines have been seen among us for these thirty years. Yet did the engineers of the day no more perceive and seizetheiradvantages than they did those of railways. But, after the perception and talent of various persons, who were in business had, for the purpose of adapting them to the necessities of their different trades, so improved railways and locomotive engines, as to have rendered the latter capable of runningregularlyupon the former, at rates of from five to eleven miles an hour, forth came our engineers, and, claiming both inventions as their own, set themselves up as having enlarged the boundaries of science, enabled man to outstrip the fleetest animals, and almost to vie with the winds!

And, last of all, I ask, to whom are we indebted for the latest important discovery, by which unprofessional perception has shewn, that whateveryengineer of the present day had pronounced to be, not only a mathematically-demonstrated, but also apractically-proved “impossibility,” is as perfectly, and as easily practicable, as it was for Columbus to make the egg stand on its end.

We have nearly 3000 miles of canals in the island; the draught on which being twenty times easier than on common roads, and the “wear and tear” equally less, it has, ever since they were first cut, been an important object to render the rate of conveyance along them rapid enough to induce persons to travel from place to placeonthem, as well as to send their goods by them.

This became more particularly important, when, in consequence of the rapidity attained on railways, it was found that they could combine the conveyance of passengers with that of goods; and I do not hesitate to say, that any engineer, who had, in 1825, informed the Canal interest that he had discovered a method by which conveyance could be effected on canals at the same rate as by mail-coaches, or post-chaises on turn pike-roads, and for one-tenth of their expense of draught, might have made terms with them for the adoption of this method, which should have brought him in above 100,000l.sterling.

But, so far from the engineers of the day informing the canal interest that they could do any thing for them in this case, they universally preached despair with respect to it; satisfying them, by mathematical demonstration, that, owing to the resistance of fluids to bodies moving throughthem, increasing according to the square of the velocity, rapidity of transmission along canals was no more possible than for a coal-barge to beat to windward like a cutter.

It is true they admitted that the steam-engine gave them power enough to more vessels on canals as rapidly as steamers move on rivers. But, they said, owing to the surge which it wasunavoidablesuch rapid motionmustcreate, the banks of the canals would be so soon washed down, that it was impossible to avoid ruining the canals, if rapid conveyance were attempted on them. Therefore, though steam has been in use as a moving power on our rivers for above these twenty years, it has never yet been employed for a similar purpose on our canals, except in the way of experiment.

In consequence of these things, they could do nothing to meet the wishes of the canal interest: and, in the evidence on the Birmingham Railway, before the Lords’ Committees, on the 29th June, 1832, it is stated, in answer to an inquiry as to what was the quickest kind of canal communication between London and Birmingham, that “The fly boats go by the shortest route, and they are three days and three nights on the road.” Now as this “shortest route” is 152½ miles, it appears that the quickest rate of canal conveyance by “fly boats” was less than 2⅛th miles an hour; while in answer to the question, “What time is occupied by the slow boats?” it is replied, “About six or seven days: they seldom travel at night.”

In this state of despair on the part of the canal interest, and amid this chorus of “impossible,” on the part of the whole of the engineers of the present day, a private gentleman (William Houston, Esq. of Johnstone Castle) became impressed with the opinion that, equally as we can, by giving it rapid motion, cause a flat stone to skim over the surface of the water (as boys do, when playing at what they call “making ducks and drakes”) so might we, by giving rapid motion to a properly constructed boat an a canal, cause it, not only to skimoverthe water, so as to avoid raising the wave which the engineers had pronounced equally unavoidable as it would be fatal to the banks of canals, but also much more easily than boats can be drawnthroughthe water.

On putting this thought into practice, Mr. Houston found the result to be what he had anticipated; and the consequence is, that it is now established by actual anddailypractice on the Paisley and Ardrossan Canal, that boats which carry more passengers than (on an average) the locomotive engines, of twenty and thirty horse power each, draw on the Liverpool and Manchester Railway, at rates of from 15 to 20 miles an hour,[62]are drawn from Johnstone to Glasgow at the rate of ten miles an how bytwohorses only; while a velocity so high as 15 miles an hour has been attained: “and this speed was not limited bythe labour of the draught, but bythe power of speedof the horses.”

In other words, that which the whole of the engineers of the present day had pronounced anddemonstratedto be utterly impossible, is now constantly done, several times every day, as a regular passenger-carrying business, on the Paisley and Ardrossan Canal.

And, although the charges for this rate of conveyance are “just one-half, and one-third, of the fares in the Liverpool Railway coaches, the profits are such, as to have induced the proprietors to quadruple the number of boats on the canal;” while the passengers, instead of being boxed up asin the railway coaches, and exposed to the weather, as in the railway “second class carriages,” may either take exercise on the decks, or seat themselves in the long cabins of these passenger-boats.

As this method of rapid canal conveyance is becoming generally adopted, this simple idea of a private gentleman, has not only put to shame the whole of the engineering talent of the present day, but has also possessed the kingdom of nearly 3000 miles of liquid way, which, as if by the stroke of a wand, are raised from the low value of heavy, miry, cross country roads, on which no greater velocity than that of a carrier’s waggon could be attained, to the high value, not merely of the best turnpike-roads, on which the conveyance of persons, at mail-coach and post-chaise rates, can be effected, but also of routes on which two horses can (and daily do) draw one hundred people as fast and (I understand)moreeasily than four draw sixteen persons on our best mail-coach roads, with less than one-twentieth the wear and tear to the vehicles than takes place as to coaches on roads: on advantage, the money value of which will be inadequately expressed by saying, that as it would cost above thirty thousand pounds per mile to give us roads on which the same power could do the same work, with the same small expense of wear, tear, and current expenses, the simple thought of a private gentleman, whom the engineers of the day would have pronounced a “nobody” in point of scientific authority, has possessed the nation of what it would have cost above one hundred millions sterling to purchase, had said engineers been employed to procure an equal amount of roads, of equally easy draught, and little “wear and tear” for us.

Yet are these gentlemen looked up to as infallible; and allowed to fulminate their anathemas with respect to what they please to pronounce “impossible” as if they were omniscient.

The actual charges the passenger-boats, which now run daily (at the rate of ten miles an hour) between Johnstone and Glasgow, are, one penny per head per mile in the first cabin, and three farthings per head per mile in the second cabin.

How much less these charges are than turnpike-road fares, need not be pointed out: my object being to submit, that equally as our canals having for these three-quarters of a century remained only routes for goods at carriers’-waggon rates, when they might, all along, have been routes for passengers at the highest rates whereat it is possible for horses to go, proves that the engineers of the day knew nothing whatever of a subject which they professedfully and entirelyto understand—so may they be equally ignorant of the merits of the proposition which they have so ridiculed and condemned me for presuming to bring forward; and which is, as exactly whattheyterm it, as theydemonstratedit to be “impossible” to be conveyed at mail-coach and posting-rates along canals.

Now, great as is the honour due to the engineers of the present day, for thus permitting the accidental thought of a private gentleman to possess the nation (as it were by the stroke of a wand) of 3000 miles of liquid way, over which conveyance may take place at rates of from 10 to 15 miles an hour, for one-tenth the expense, and less than one-tenth of the wear and tear that takes place on roads, after they haddemonstratedthat no greater rate than two or three miles an hour could be attained on said routes; and, greatly as the canal interest must be indebted to them, for suffering them (the canal interest), in consequence of saiddemonstration, to lose the millions upon millions they might have received of the public, for conveyance at these rates of 10 or 15 milesan hour, during the three-quarters of a century canals have been in operation among us—equally as the engineersthusdeserve public gratitude, do they also deserve it for the manner in which they have suffered the law of motion, by means of which the stage-coachman “swings” his vehicle up the first part of a hill, to remain useless with respect to that improvement of our turnpike-roads which it admits of; and which, though not equal in money-value to the “idea” of Mr. Houston, which has just been described, is yet highly important.

The law itself is “old as the hills;” and, notwithstanding that the advantage taken of it by stage-coachmen when coming to the bottom of a rise, is notquiteof such long standing, yet is it old enough to have pointed out an advantageous alteration in the arrangement of all our turnpike roads, had the engineers under whose direction said roads were laid out, but availed themselves of it.

By the table given on page33it appears, that if a vehicle be moving on a level with a velocity of 2¾ miles an hour, its momentum will (under the circumstances there stated) carry it up a rise to three inches of perpendicular height: while, if the rate of motion be twice, and four times 2¾ miles an hour—i.e. 5½ and 11 miles—the momentum will carry it up heights of one foot and four feet respectively: and the following table gives the altitudes due to every intermediate mile of rate:

Bodies moving on levels at the under mentioned velocities, the motions of which are changed from horizontal to ascending, by means, either of angular or circular ascents.

Have moments, which (friction being counteracted) will cause them to rise to the under-mentioned heights above the level where those velocities were attained, let the rate of rise, or angle of ascent, be what it may.

MILES PER HOUR.

FEET.

INCHES.

3½

6⅜

2⅜

7⅝

1⅝

8½

9⅝

7¾

6⅝

6¼

6⅝

7⅞

9⅞

0⅝

4½

A velocity of six miles an hour being thus capable of giving momentum sufficient to enable any vehicle to surmount an ascent of above one foot in perpendicular height, let the angle of ascentor rate of rise, be what it might, it has been necessary only to lay out our turnpike-roads in alternate short levels, with sharp rises of one foot in height between them, similar to the line below, to render all our roads level, in point of effect, to every vehicle which went at the rate of six miles an hour; since, as thecontinueddraught of the horse would overcome, neutralise, and (as relates to its counteractive effect) annihilate the friction of the wheels and axes during the ascent, the momentum imparted by that velocity would enable the vehicleof itselfto rise up, and surmount the ascent, without anyextraeffort on the part of the horse: while, supposing that the practice of stage-coachmen were to be imitated, and the horses of these six-miles-an-hour vehicles pushed to a pace of twelve miles an hour for a few yards before the wheels actually touched these rises, so as to give the vehicle a velocity of 12 miles an hour at the moment of itsbeginningto ascend them, the momentum imparted by this velocity would carry the vehicle up four feet nine inches perpendicular, instead of one; so that the road might be laid out in alternate levels and rises of four feet.

It is true that, supposing this principle to be acted on, half the width of the road must be left in the usual manner, in order to enable waggons, which do not move faster than two or three miles an hour, to pass over it. But as the slow rate of two miles an hour will give momentum enough to admit of a rise of 1⅝ inches being surmounted, the principle might be taken some advantage of, even on the half of the road appropriated to waggons; since rises not exceeding 1½ inches each, could be surmounted by vehicles which did not move faster than two miles an hour.

However, leaving the waggon-half of the road to the usual arrangement, the advantage of, as it were, doing away with all hills and rises, and rendering all our roads level (in point of effect) to all vehicles travelling at the rate of six miles an hour, might have amply repaid the expense of this suggested alteration in theformof the roads, had the engineers under whose direction they were cut, but laid them out in that manner: while, supposing that a rate of 16 miles an hour could be attained by pushing the horse to a gallopjust beforereaching the ascent, the levels and rises might be laid out in gradations of eight feet each instead of four feet.

But let the heights of these proposed elevations be what they might, the advantage of (in effect) doing away with all hills and rises, and of rendering our roads level to us all over the kingdom would be attained; which might prove ample reward for varying the mere form of the roads; and would not, I think, have been unworthy the notice even of our omniscient engineers; notwithstanding that the way in, and degree to which they have neglected and slighted this law of motion, with respect to its application to railways as well as to turnpike-roads, proves them, one and all, to have been equally percipient of its advantages, as they were of the practicability of rapid conveyance on canals; and as theyareof the merits of the method of transmission which the individual who has now the honour of addressing you is presumptuous enough to think deserving even of THEIR attention: omniscient as they deem themselves relative to it; and omnipotent as they have, hitherto, proved, with respect to its condemnation and rejection.

Should I, however, be fortunate enough to meet with any who will measure the competence of these gentlemen thus to condemn, by the following standards, I cannot but trust that my appeal from their decision will be favourably received.

The question, divested of technicalities, resolves itself into the three following considerations.

First, can we construct iron (or any other kind of) tunnels, such as would be requisite for the operation of the principle? Secondly, can we construct air-pumps large enough to exhaust from the said tunnels with the necessary rapidity? And, thirdly, can we make steam-engines powerful enough to work these air-pumps?

Now as there is no one who denies that we have the power of making tunnels of any size, not exceeding (say) twelve feet in diameter, nor that we can form the separate segments, or pieces, in which such tunnels might be cast, into cylindrical “lengths,” of from ten to fifteen feet each, so as to lay them down and connect them as (suppose for the present) gas mains are laid down and united—as no one denies this, the second question, relating to the air-pumps, is the first to be replied to.

In 1827 there were, in Great Britain, 284 smelting furnaces; the quantity of iron made during that year by which, was 690,000 tons.

Blast apparatus being as indispensable appendages to smelting furnaces, as the flux is to the ironstone which is to be smelted in those furnaces, it follows, that (with the possibility of exception where one blast apparatus may be made to serve more than one furnace) there must, seven years ago, have been 284 sets of pneumatic apparatus for urging the fires of these furnaces to the necessary intensity, by forcing currents of air into them. These apparatus formerly varied in form, from common bellows on a large scale, to the diversities of the “water blast.” But the whole of these varieties of blast apparatus are now found so inferior to what are termed “blowing cylinders” that no one who erects a smelting furnace ever thinks of applying to it any other means for urging its fire than this latter description of apparatus.

These “blowing cylinders” are all air-pumps on a large scale; differing from the common air-pump only in being of iron instead of brass; in having their valves so arranged as to cause them, instead of exhausting airfromthe vessel they operate on, to blowintoit; and in their being as much larger than a common air-pump as the “monster mortar” used at the late reduction of the citadel of Antwerp is than a boy’s sixpenny cannon.

The largest of this kind of air-pumps that I have seen was nine feet in diameter, by an equal or rather superior height; though an iron-founder has informed me that he once cast one of eleven feet in diameter. And it is unquestionable, that it will require only the preparation of the necessary moulding and boring, &c. &c. apparatus, to make any number, of any diameter we please, not exceeding (say) twelve feet. Supposing them to be 11.3 feet in diameter, their area would be equal to 100 square feet; and, supposing the velocity with which their pistons moved, to be only half that of the average velocity of the pistons of steam-engines, each of these air-pumps would cause 11,000 cubic feet (i.e. about 70,000 gallons) of air, to pass through each of them per minute; which air would be drawn out of, or forced into, any thing, according as the valves were arranged.

Every one of such pumps that was used to exhaust air from a tunnel of eight feet in diameter would produce a current in it, moving at the rate of two miles and a half an hour; while, supposing that its piston moved at the same velocity whereat the pistons of steam-engines in general move, this current would pass through the tunnel at the rate of five miles an hour.

It being evident, then, that it is necessary only properly to arrange the size and number of the pumps, to cause the atmosphere to rush along the tunnel at any rate we desire; and it being a fact that we have, in daily operation, about 300 such air-pumps as these (though not quite so large)there is only one remaining shelter behind which these “impossibleists” can pretend to screen themselves.

The first steam-engine which Boulton and Watt erected in their manufactory of Soho as a specimen for the examination of those who wanted such machines, was about the year 1780. The exact number we now have among us there are no means of ascertaining. But the authority which I have quoted for the existence of 15,000 steam-engines in Great Britain, states them to be of the average power of twenty-five horses.

If this may be received, the whole amount of “horse power” in operation among us in 1831 was equal to that of 375,000 horses. And even though it should be necessary to lower this down to M. Dupin’s estimate of 200,000 horses in 1824, there would remain an aggregate ample for our purpose. Since, if there was not in 1790onesteam-engine in Manchester, while there are now nearly 300 there, it may safely be assumed that so much the larger proportion of the thousands of them which are now spread over the kingdom have been made within the last thirty years, as to admit of its being fairly inferred that we have, for many years past, constructed them at a rate equal to ten thousand horses’ power per annum.

Yet, with these facts almost as easily verified as it would be to obtain copies of all the newspapers published in the kingdom, and with some of these engines so large as to be equal to 300, or 500, or (as quoted in page46) even 1000 horses’ power, do these “impossibleists” say we cannot obtain power enough to work the air-pumps we should require to pump the air out of the tunnel. Just as, twenty years ago, they said we could not use steam to carry us across the seas, nor gas to light our streets.

In reply to a demand of the great Lord Chatham that a certain naval force should be ready by a certain day for an expedition be contemplated; and which, the nature of the service rendered it necessary should be despatched as promptly as it was determined on, the then first lord of the admiralty stated, as an intended conclusion to several notes (or messages) which had passed between the two departments on the subject, that “it could not be done, because it wasimpossible.” “Inform the first lord from me,” said the minister, “that the service of the state requires theimmediatedespatch of the expedition: and that if he, with the military marine of the kingdom at his order by virtue of his office, and the commercial marine at his command by the course of hiring transports, delays the departure of the expedition becausehedeems it impossible, I will impeach him.” Under this alternative, the “impossibility” vanished, and the expedition sailed.

Now as the facts which I have adduced relative to the existence of all the necessary means for rendering importantly available to general use the principle here described, prove that the gentlemen of that profession which is devoted to the practical application of mechanical science to the public service have, for these seven years, proclaimed to be “impossible” that which is as easily practicable as it was for the first lord of the admiralty to prepare the naval part of the expedition referred to, I leave it to themselves to make evident why they should not be impeached, as equally traitors to the cause of practical science, as the first lord of the admiralty would have been to the state, had the expedition not sailed at the period the minister required.

Those who will give themselves the trouble of the calculations necessary to establish the truth of the preceding statements relative to the effect of momentum, it will be unnecessary to remind ofany of the occurrences which prove it. But those who do not choose to take that trouble, may be reminded, that a circumstance often witnessed, gives practical demonstration of the accuracy of these statements.

During certain adhesive states of the crust of the road, it is frequently seen when travelling, that the pressure of the wheels causes particles of earth to adhere to, and rise from the ground, sticking to the tire of the wheel.

The adhesion of these particles of earth being, however, soon destroyed by the centrifugal force imparted by the revolution of the wheel, they become, the momentitloosens them from the wheel, and allows the other influence to operate, projected in directions varying according to the position of the part of the wheel to which they adhered, at the moment of their quitting it.

Some of them, being carried to the top of the wheel, fly forward; but the majority, leaving the wheel at about the height of the axle-tree, become projected vertically, and are seen bobbing up and down by the windows of the carriage, somewhat like motes in the sunbeam.

Their thus rising and falling may, perhaps, hitherto have been observed, without being regarded as demonstrative of any principle which may be rendered subservient to our purposes. But as they are, in point of fact, evidences, that the momentum imparted by the velocity at which the tire of the wheels is revolving, will cause bodies to rise to the height of three or four feet perpendicular, above the point of the wheel from which they fly; and as this velocity is exactly commensurate with that at which the carriage goes over the ground, they are unquestionable proofs, that, provided friction be annihilated as relates to counteractive effect, by the continued operation of the moving power, the vehicle itself would ascend an inclined plane ofanyrate of ascent, to the same height to which they rise above the position of the part of the wheel they adhered to, at the moment of their flying from it.

But, to leave this question relative to momentum, and return to that of the steam-engines and air-pumps.

It being the property of air to neutralise, or absorb, a smaller portion of whatever impulse may be imparted to it, than, perhaps, any other ponderable medium nature offers us, the power of the steam-engines which operated on the air-pumps that exhausted air from the tunnel, might be brought to bear,—and that too, without their energy being so diminished as even toapproachan insuperable objection—on the vehicles in it; and an effect in consequence produced, which we cannot, at first, conceive to be possible.

It is evident, that it will not require the power of the engines (each equal to several hundred horses’ power), by which the air-pumps would be worked, to move one, or even many vehicles. What then will become of the surplus power? Will it be lost in overcoming the friction of the air, as adverted to at page41; or, rather, may it not operate to increase the rate at which the vehicles will move? And if so, how many times will the rate at which we may be conveyed, exceed that at which we now travel, and what is the limit that will be attained in this particular?

It is well known that air will rush into a vacuum at the rate of nearly a thousand miles an hour. Now although it is no more expected we should be conveyed at any such rate as that, than it is intended we should be placed in a vacuum, yet are, both this almost inconceivable velocity, and what is generally expressed by the term “vacuum,” so connected with the subject of consideration, that it becomes unavoidable to advert to them, injurious as they must prove, and strongly as they will array our preconceived notions and prejudices against the proposition.

It cannot be denied that we have the power of laying down a tunnel, such as has been referred to, and of adapting a railway to the inside of it, for any distance we please: and, though it may not be in our power so to connect the separate “lengths” or cylinders which compose it, as to render the joints perfectly air-tight against a vacuum, yet, with reference to the trivial degrees of exhaustion necessary for the purpose here contemplated, every joint may most easily be made “air-tight”: since, supposing the degree of exhaustion to be equal to the pressure at which gas is forced through the mains of a public company whose works I know, a load of above 100 tons would be carried along a tunnel of eight feet in diameter, at whatever rate the air was pumped out of it. Equally certain, as it therefore becomes, that we have the power of extending this tunnel at pleasure, is it, that the power of making and working any number of air-pumps, such as have been referred to, will enable us to exhaust from, and consequently cause air to rush through it, at rates so vastly exceeding any at which we now travel, that our preconceived notions and prejudices cause us to look on the proposition as both impossible and absurd.

One of the circumstances which at first strikes us as fatal to the proposition, is the inability to respire, which we all feel we should be liable to, if conveyed rapidlythroughthe air. A moment’s reflection will, however, enable us to see that this objection has no application whatever to the case. It is not proposed that we shall be conveyed rapidlythroughthe air, but that we shall cause air, which we have first set in rapid motion,to convey us along with it,as fast as itself goes: a state of things so different from going through, or against, and meeting the air, that our supposed objection does not apply to the case.

Stating facts will, however, be the best way of settling this question; and for this purpose the experience of our aeronauts is referred to. Much as they have sometimes been inconvenienced from the rarity of the air, at the heights to which they have ascended, yet have we never heard them complain of being unable to breathe freely, owing to the velocity with which they were carried along over the earth’s surface, notwithstanding that they have been conveyed at rates of 70, 80, and, in one instance, 160 miles an hour. And why? because that which was the cause of motion went with them.—“I had not,” says Lunardi, in his account of the first ascent ever made in England, “the slightest sense of motion from the machine. I knew not whether I went swiftly or slowly—whether it ascended or descended—whether it was agitated or tranquil, but by the appearance or disappearance of objects on the earth.” Rapidly, therefore, as they have moved, yet have they felt as if in a calm. Now exactly similar in point of respiration, would be the feeling of those who might be conveyed in the proposed tunnel. The air, being the cause of motion, must go,at least, equally fast as it drove them, and necessarily be wherever they were. Let the rate of motion therefore, be what it might, the feeling of those who experienced it, must prove that of being in a perfect calm.

Nor are the objections we at first conceive, relative to the effect which pumping air from the tunnel, and producing what only the word vacuum (inapplicable as it is) will enable us to convey the idea of, at all more tenable. The degree to which air would be exhausted from the tunnel might scarcely ever be sufficient to sink a barometer two inches lower than one exposed to the atmosphere stood at; so that even were we exposed to it no inconvenience would be felt.[69]But wenever shall be exposed to it, any more than those who witness the cruel experiment of putting a mouse under the receiver of an air-pump, and then exhausting it, are exposed to what the little animal suffers. Between those whoseeand the poor creature whichfeelsthe effect of the apparatus, is the side of the receiver. And between the part of the tunnel in which the exhaustion, or rather the difference of density is, and the passengers in the vehicle, would be theendof the vehicle; so that thoughclose to themwould be an atmosphere rarer than (we will suppose) it might prove pleasant to be in, yet would the atmospherethey actually were inbe the same as that of the air at large. No inconvenience, therefore, can be experienced in this particular.

Equally untenable is the idea we take up, that it will be impossible so to adapt the ends of the vehicles to the inside of the tunnel, as to cause them to act as pistons in preventing the passage of the air by them, without occasioning friction to a degree which should deprive us of all the advantages the air would otherwise give, as a mean of communicating motion.

In the last carriage which I had for the tunnel I constructed at Brighton, there was a space of above an inch and a half in width left all round between thepistonpart of the carriage and the tunnel, through which air rushed unimpeded. Yet did not this “windage,” or leak, though equal in the aggregate, to an aperture of three square feet, prevent the carriage from springing forward to the impulse of the air-pumps, with a readiness I was surprised at. Nor did it ever cause the leastperceptiblediminution in their effect; owing to the small quantity of air that passed through it, in comparison with the immense quantity exhausted by the pumps.

When the Brighton Committee rode in that tunnel, one of them brought with him a mountain barometer, that he might ascertain the degree of “vacuum” or exhaustion necessary to move the carriage. This barometer was accordingly suspended in the part where the “vacuum” was to be produced, and the vernier adjusted with the greatest accuracy. But to his surprise the degree of exhaustion was not sufficient to lower the barometer in theleastdegree. Being aware of this, I had spirit gauges previously prepared, one of which was fixed in the end of the carriage. But even this gauge, though nearly fifteen times more sensitive than the barometer, was affected hardly enough to be visible, the amount of “vacuum” indicated by it, being only about ten grains per square inch, orlessthan the ten-thousandth part of a vacuum.

Nor would the quantity of air that rushed by thepiston-endof the carriage be at all important, even when travelling atverygreat velocities, and with heavy loads. In a tunnel of the diameter which would be proper for such lines as those to Bristol, or South Wales, the pressure requisite to move a load of 100 tons would not be more than about 100 grains per square inch; which would cause air to rush past the piston-end of the carriage at the rate of about 30 feet per second. Therefore, even could no better adjustment of the piston-end of the carriage and the inside of the tunnel be effected, than took place with respect to that at Brighton, only 90 cubic feet of air per second would rush past, even were the carriages standing still; which is only one-tenth of what the air-pumps I used there were capable of exhausting in the same time; while, on such a line as the Bristol, or South Wales, it would not be one-hundredth of what the exhausting apparatus would take out in the same period; so that not one-hundredth of the power would be lost by it: and even this hundredth could easily be reduced to a thousandth: the space left between the piston-end of the carriage in the tunnel at Brighton beingpurposelyan inch and a half in width, in order that I might shew, by actual proof, how utterly unimportant wasthatobjection which engineers of thehighest name and reputation had assured me must,inevitably, prove fatal to the motion ofanycarriage inanytunnel.

And as the carriage, instead of standing still, would be moving forward, the loss of power, which would, otherwise, result from the pressure requisite togive the velocityas well as move the load, would be equally unimportant as that arising from the pressure requisite to move the load alone.

With pressures so trivial as these capable of producing practical effects, and with it fully practicable so to adjust the “piston” part of the carriages to the tunnel, as to render this “windage,” or leak, perhaps less than one-hundredth of that which Ipurposelycaused in the tunnel at Brighton, there can be no difficulty, either in preventing any important quantity of air from rushing past the carriages; or in so connecting the “lengths” of which the tunnel would be composed, as to render the joints air-tight.

And as there arenoobjections which the engineers can bring forward, that cannot be replied to in an equally satisfactory manner, I need not trouble you with any additional answer to them.

It is now four years ago since the locomotive engine competition took place on the Liverpool and Manchester Railway. In all probability no proprietor of the Kensington Canal happened to be present at that contest; yet is it equally probable that all were as fully convinced of the fact from the accounts which appeared in the newspapers, as if you had seen it. Now though I cannot give the conviction arising from the evidence of your senses, yet can I give stronger evidence than the public vehicles of intelligence gave as to that competition, by referring you to the public authorities and records of Brighton, to know whether I did not carry an appointed number of its inhabitants to and fro, as the locomotive engines went during that competition; “when,” says Mr. Treasurer Booth, in his “Account of the Liverpool and Manchester Railway,”—“the prescribed distance, it should be understood, was, owing to the circumstances of the railway, obliged to be accomplished, by moving backwards and forward on a level plane of one mile and three quarters in length.” I did not, it is true, carry those gentlemen so far as those engines went. Nor, indeed, was there any occasion for it. Had it been necessary, they could have continued riding to and fro in my tunnel, as long as the locomotives ran to and fro on the railway. But, as when they had satisfied themselves that there was no trickery in the motion of the carriage, and that it wasreallymoved by the air, they had, then, seen all that it was necessary to see, to convince them that a longer tunnel would enable me to move a carriage equally far, as a longer railway would have admitted of the locomotive engines going, they gave over riding, “because,” as the Editor of the Brighton Herald says, in the extract which I have quoted from that paper, “because they became so convinced that the invisible and intangible medium we breathe, might be rendered a safe and expeditious means of getting us from one place to another, as to be tired of riding.”

Were it necessary for your interest that a gas-pipe should be laid throughout the line you propose, your inquiry of the engineer you might employ would be, not whether the gas would pass through such a length of pipe, because you know that to have been long established, and to be every day acted upon, but what would be theexpenseof it; that is, it would be a money question, not a question of practicability.

The tunnel I constructed at Brighton was nearly eight feet in diameter, while the air-pumps I adapted to it were large enough to make an artificial wind blow through it at the rate of ten miles an hour. And doubling, tripling, quadrupling, &c. &c. the size, or number of the pumps, would have doubled, tripled, &c. &c. the rate at which this wind blew.

A common size for gas mains is eight inches. Were it propounded to you—“Can a mouse run through a rat-hole, let that bole be as long as it may?” your answer would not be dubious. Why, then, if it be proved, that we can, with pneumatic apparatus of an almost infinitely less efficient nature than that which I purpose using, make air move through smaller pipes five, fifteen, or even fifty miles long,[72]should any doubt be entertained whether air-pumps will cause it to move through one of eight feet in diameter; more particularly, when it is well known, that the larger the pipe the less the proportionate friction; and when your line will be little more than two miles long.

The pressure by which the gas is driven through the pipes of the work I know the most of, is equal to an ounce and a half per square inch. A similar pressure on the carriage in my tunnel would have moved above one hundred tons. The length of your line would be only about eighty times longer than the tunnel I constructed; and as the area of your tunnel would be nearly 150 times larger than the eight-inch mains through which the gas is carried many times farther than the length of your line, there need be no more question as to whether, or not, the principle will act throughout your line, merely because it is eighty times longer than my tunnel, than there is whether gas would pass through eighty lengths of gas-pipe.

And as the joints which connect the different “lengths” of gas-pipes can easily be made air-tight, so could the “lengths” and joints of the tunnel. “Under the trivial degree of exhaustion which will be necessary,” says the Report of the Russian Engineer Officer, “rendering the tunnel sufficiently air-tight will be far less difficult than is at first supposed. Indeed, I see so many different ways of doing it,” continues the Report, “that I am satisfied it would not, in practice, prove more difficult than, nor, indeed, so difficult as, causing some canals I have seen, to retain the water let into them.” Following up the illustration which this gentleman thus gives, I beg to assure you I will guarantee that the tunnel shall not leak, or let air improperly in, so much as I see the basin of your canal leaks water out.

Adverse as were the original circumstances of the great father of canal navigation in England, yet did he put to signal shame the opposition and predictions of the engineers who proclaimed him a madman for pretending that it was possible to carry a canal over a navigable river. Ten thousand times more mad as the engineers of the present day proclaim me, and a hundred thousand times more absurd and “impossible” as they have pronounced my proposition to be, yet, owing tohaving in my favour (what Brindsley had not in his) the circumstance of my principle having been tried, I am enabled to oppose to their ridicule and sneers the FACT that I have proved it on a scale, which, as relates to size, was fully, and ineveryparticular practical; while it was less than practical in point of length, only because no individual could do that which it requires a public company and an act of parliament to do, that is, lay it down between places for actual trade.

Short, however, as it was, yet was it many times longer than the pipes through which gas was first carried, to prove the practicability of lighting our streets with that illuminator: while its length was great enough to be equally conclusive, as the movement of the first steam-vessel built by the introducer of steam-navigation.

“When,” says Fulton, “I was building my first steam-boat at New York, the project was viewed by the public either with indifference or with contempt, as a visionary scheme. My friends, indeed, were civil, but they were shy. They listened with patience to my explanations; but with a settled cast of incredulity on their countenances. I felt the full force of the lamentation of the poet:

‘Truths would you teach, to save a sinking land,All fear, none aid you, and few understand.’

“At length the day arrived when the experiment was to be put into operation. To me it was a most trying and interesting occasion. I invited many friends to go on board, to witness the first successful trip. Many of them did me the favour to attend as a matter of personal respect; but it was manifest that they did it with reluctance, fearing to be the partners of my mortification, and not of my triumph.

“The moment arrived in which the word was to be given for the vessel to move. My friends were in groups on the deck. There was anxiety, mixed with fear, among them. They were silent, and sad, and weary. I read in their looks nothing but disaster; and almost repented of my efforts. The signal was given; and the boat moved on a short distance, and then stopped—and became immoveable.”

Whenmyopponents can prove, that because Fulton’s first steam-vessel would, on its first trial, move only the “short distance” stated in the above quotation, it was, therefore, impossible to move any other vessel farther by means of steam, I may heed the clamour they raise about my proposition not being practicable through a long line of tunnel.

Until then, I can consider it only as a proof of their knowledge being on a par with the wisdom of that most learned opponent of Galileo’s theory that day and night are occasioned by the revolution of our planet on its axis, who, in answer to the query, “How then is it that the sun gets back to, and always rises in the east of a morning?” replied, that he went back by night, when nobody could see him.

In concluding, I will endeavour to guard against a circumstance that may otherwise be injurious to me, by an observation. You will perceive that the evidences which I have quoted have been in existence six or seven years. How then, it may be inquired, is it, that a method which is spoken of so highly as those evidences speak of this mode of conveyance, should have remained seven years without having been put into actual practice, or brought any nearer to that consummation than it was when those documents were written?

During the many years which elapsed between the period of Columbus’s first proposing toFerdinand and Isabella the discovery of America, and their actually setting him afloat to do it, he sent his brother Bartholomew to England, to lay the proposition before our Seventh Henry, who, he expected, would entertain it. Henry did entertain it; and would have possessed England of the southern more firmly than she afterwards became possessed of the northern half of America, but for the misfortune which prevented Bartholomew Columbus from approaching him, till Isabella had agreed with, and dispatched Columbus himself.

“In his voyage to England,” says the historian of America, “Bartholomew Columbus had been so unfortunate as to fall into the hands of pirates; who, having stripped him of every thing, detained him a prisoner for several years:” reducing him to such poverty, that when released from captivity, he could in no other way obtain the means of procuring a dress fit for his appearance before the king, than by employing himself in drawing maps.

Circumstances which, morally speaking, areexactlysimilar to this captivity and imprisonment of Bartholomew Columbus—excepting that they failed in compelling me to sign away the patent rights, to wrest which from me they were instituted—have equally hindered and reduced me: occasioning the destruction of the tunnel which I constructed to demonstrate, practically, the truth of the proposition; and depriving me of all means of proving it, except by carrying small things on an experimental scale, instead of persons on a practical one.

As relates to myself, I have no desire to obtrude the details of the oppression and injustice practised upon me, on any one.

But with respect to the subject I advocate, I am most anxious that the whole world should know that I court thefullestinquiry, and am ready to answereveryquestion.

As one proof of this, and to shew that there is nothing which I need to blush for, any more than Bartholomew Columbus had cause to blush for being imprisoned by the pirates, I beg to direct your attention to the annexed copy of the Petition I presented to Parliament; of which only an extract is given in page19. Soliciting the favour of your perusing it, I have the honour to be,

My Lords, and Gentlemen,

Your very obedient,

And most humble Servant,JOHN VALLANCE.

AS the first evidence that “the observations which will be found in the course of this letter relative to the effects of momentum, are not of such recent origin in my mind, as Mr. Badnall states his idea relative to the undulatory railway to have been in his,” I observe, that in the specification of my patent, after declining to level for the course of my tunnel by cutting through hills or filling up vallies, as is done for railways, I state, that I carry it up and down them (provided they are not precipitously abrupt) for the reason, that “the momentum it (the carriage) may thus acquire, will be advantageous in other ways than merely carrying itself forward.”

Secondly. The last sentence of the paragraph commencing “Tenthly,” in the Report of the Russian Engineer Officer, implies that that gentleman had understood what I have stated relative to this effect of momentum, from my communications to him.

Thirdly. The plan and section of the Brighton and Shoreham Pneumatic Railway, which I deposited in the County Court in 1827, and in Parliament at the beginning of the session of 1828, prove that the whole rise from Shoreham Harbour to the spot on thetopof the hillaboveBrighton (old) Church, where I intended said Pneumatic Railway should terminate, was (I forget the exact amount, but) about 180 feet: of which rise, about 150 feet took place in the last half mile; giving a rate of about 1 in 18: up which rise I looked to momentum, as theprincipalmeans of getting the 100,000 tons of goods I calculated on carrying between those places.

Fourthly. In my letter to Mr. Ricardo, in answer to his pamphlet against me, I observe, that after totally omitting to take into consideration the important effect which momentum (as well of the air itself as of the vehicle) would have in modifying the motion, and preventing the stoppage of the carriage, in the way you describe at page 21, you exclaim, “This then, is a true philosophical explanation, of what will take place in the action of a carriage impelled by atmospheric pressure!”

Against such philosophy as this I protest, in justice both to myself and the public. As the basis of lectures delivered at your Mechanics’ Institution, where

—“words of learned length and thundering soundAmaze theoperativesrang’d around,”

it may have sufficed. But when held up as a criterion by which the public mind is to take its tone for my condemnation, I am compelled to pronounce it philosophy of which its author ought to be ashamed.

These evidences being all of dates several years anterior to the period when Mr. Badnall states the idea of his “Undulating Railway” first occurred to him, I shall be liable to no charge of proposing to avail myself of momentumin consequenceof his having proposed “UndulatingRailways.”

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