One Sunday afternoon, in the spring of 1765, he went to take an afternoon walk on the Green, then a quiet grassy meadow used as a bleaching and grazing ground. On week days the Glasgow lasses came thither with their largest kail-pots to boil their clothes in; and sturdy queans might be seen, with coats kilted, trampling blankets in their tubs. On Sundays the place was comparatively deserted; and hence Watt, who lived close at hand, went there to take a quiet afternoon stroll. His thoughts were as usual running on the subject of his unsatisfactory experiments with the Newcomen engine, when the first idea of the separate condenser suddenly flashed upon his mind. But the notable discovery is best told in his own words, as related to Mr. Robert Hart, many years after:—
"I had gone to take a walk on a fine Sabbath afternoon. I had entered the Green by the gate at the foot of Charlotte Street, and had passed the old washing-house. I was thinking upon the engine at the time, and had gone as far as the herd's house, when the idea came into my mind that as the steam was an elastic body, it would rush into a vacuum, and if a communication were made between the cylinder and an exhausted vessel, it would rush into it and might be then condensed without cooling the cylinder. I then saw that I must get rid of the condensed steam and the injection water if I used a jet, as in Newcomen's engine. Two ways of doing this occurred to me. First, the water might be run off by a descending pipe, if an off-let could be got at the depth of 35 or 36 feet, and any air might be extracted by a small pump. The secondwas to make the pump large enough to extract both water and air." He continued: "I had not walked farther than the Golf-house when the whole thing was arranged in my mind."
Great and prolific ideas are almost always simple. What seems impossible at the outset appears so obvious when it is effected, that we are prone to marvel that it did not force itself at once upon the mind. Late in life Watt, with his accustomed modesty, declared his belief that if he had excelled, it had been by chance, and the neglect of others. To Professor Jardine he said that when it was analyzed the invention would not appear so great as it seemed to be. "In the state," said he, "in which I found the steam-engine, it was no great effort of mind to observe that the quantity of fuel necessary to make it work would forever prevent its extensive utility. The next step in my progress was equally easy,—to inquire what was the cause of the great consumption of fuel: this, too, was readily suggested, viz., the waste of fuel which was necessary to bring the whole cylinder, piston, and adjacent parts from the coldness of water to the heat of steam, no fewer than from fifteen to twenty times in a minute." The question then occurred, How was this to be avoided or remedied? It was at this stage that the idea of carrying on the condensation in a separate vessel flashed upon his mind, and solved the difficulty.
Mankind has been more just to Watt than he was to himself. There was no accident in the discovery. It had been the result of close and continuous study; and the idea of the separate condenser was merely the last step of a long journey, a step which could not have been taken unless the road which led to it had been traversed. Dr. Black says, "This capital improvement flashed uponhis mind at once, and filled him with rapture,"—a statement which, in spite of the unimpassioned nature of Watt, we can readily believe.
On the morning following his Sunday afternoon's walk on Glasgow Green, Watt was up betimes, making arrangements for a speedy trial of his new plan. He borrowed from a college friend a large brass syringe, an inch and a third in diameter, and ten inches long, of the kind used by anatomists for injecting arteries with wax previous to dissection. The body of the syringe served for a cylinder, the piston-rod passing through a collar of leather in its cover. A pipe connected with the boiler was inserted at both ends for the admission of steam, and at the upper end was another pipe to convey the steam to the condenser. The axis of the stem of the piston was drilled with a hole, fitted with a valve at its lower end, to permit the water produced by the condensed steam on first filling the cylinder to escape. The first condenser made use of was an improvised cistern of tinned plate, provided with a pump to get rid of the water formed by the condensation of the steam, both the condensing-pipes and the air-pump being placed in a reservoir of cold water.
"The steam-pipe," says Watt, "was adjusted to a small boiler. When the steam was produced, it was admitted into the cylinder, and soon issued through the perforation of the rod and at the valve of the condenser; when it was judged that the air was expelled, the steam-cock was shut, and the air-pump piston-rod was drawn up, which leaving the small pipes of the condenser in a state of vacuum, the steam entered them, and was condensed. The piston of the cylinder immediately rose, and lifted a weight of about eighteen pounds, which was hung to the lower end of the piston-rod. The exhaustion-cock was shut, the steam wasre-admitted into the cylinder, and the operation was repeated. The quantity of steam consumed and the weights it could raise were observed, and, excepting the non-application of the steam-case and external covering, the invention was complete in so far as regarded the savings of steam and fuel."
But although the invention was complete in Watt's mind, it took him many long and laborious years to work out the details of the engine. His friend Robison, with whom his intimacy was maintained during these interesting experiments, has given a graphic account of the difficulties which he successively encountered and overcame. He relates that on his return from the country, after the college vacation in 1765, he went to have a chat with Watt and communicate to him some observations he had made on Desaguliers' and Belidor's account of the steam-engine. He went straight into the parlor, without ceremony, and found Watt sitting before the fire looking at a little tin cistern which he had on his knee. Robison immediately started the conversation about steam; his mind, like Watt's, being occupied with the means of avoiding the excessive waste of heat in the Newcomen engine. Watt all the while kept looking into the fire, and after a time laid down the cistern at the foot of his chair, saying nothing. It seems that Watt felt rather nettled that Robison had communicated to a mechanic of the town a contrivance which he had hit upon for turning the cocks of his engine. When Robison therefore pressed his inquiry, Watt at length looked at him and said briskly, "You need not fashyourself any more about that, man. I have now made an engine that shall not waste a particle of steam. It shall all be boiling hot,—ay, and hot water injected, if I please." He then pushed the little tin cistern with his foot under the table.
Robison could learn no more of the new contrivance from Watt at that time; but on the same evening he accidentally met a mutual acquaintance, who, supposing he knew as usual the progress of Watt's experiments, observed to him, "Well, have you seen Jamie Watt?" "Yes." "He'll be in fine spirits now with his engine?" "Yes," said Robison, "very fine spirits." "Gad!" said the other, "the separate condenser's the thing; keep it but cold enough, and you may have a perfect vacuum, whatever be the heat of the cylinder." This was Watt's secret, and the nature of the contrivance was clear to Robison at once.
It will be observed that Watt had not made a secret of it to his other friends. Indeed, Robison himself admitted that one of Watt's greatest delights was to communicate the results of his experiments to others, and set them upon the same road to knowledge with himself; and that no one could display less of the small jealousy of the tradesman than he did. To his intimate friend Dr. Black he communicated the progress made by him at every stage. The Doctor kindly encouraged him in his struggles, cheered him in his encounter with difficulty, and, what was of still more practical value at the time, helped him with money to enable him to prosecute his invention. Communicative though Watt was disposed to be, he learnt reticence when he found himself exposed to the depredations of the smaller fry of inventors. Robison says that had he lived in Birmingham or London at the time, theprobability is that some one or other of the numerous harpies who live by sucking other people's brains would have secured patents for his more important inventions, and thereby deprived him of the benefits of his skill, science, and labor. As yet, however, there were but few mechanics in Glasgow capable of understanding or appreciating the steam-engine; and the intimate friends to whom he freely spoke of his discovery were too honorable to take advantage of his confidence. Shortly after Watt communicated to Robison the different stages of his invention, and the results at which he had arrived, much to the delight of his friend.
It will be remembered that in the Newcomen engine the steam was only employed for the purpose of producing a vacuum, and that its working power was in the down stroke, which was effected by the pressure of the air upon the piston; hence it is now usual to call it the atmospheric engine. Watt perceived that the air which followed the piston down the cylinder would cool the latter, and that steam would be wasted by reheating it. In order, therefore, to avoid this loss of heat, he resolved to put an air-tight cover upon the cylinder, with a hole and stuffing-box for the piston-rod to slide through, and to admit steam above the piston, to act upon it instead of the atmosphere. When the steam had done its duty in driving down the piston, a communication was opened between the upper and lower part of the cylinder; and the same steam, distributing itself equally in both compartments, sufficed to restore equilibrium. The piston was now drawn up by the weight of the pump-gear; the steam beneath it was then condensed in the separate vessel so as to produce a vacuum, and a fresh jet of steam from the boiler was let in above the piston, which forcedit again to the bottom of the cylinder. From an atmospheric engine it had thus become a true steam-engine, and with much greater economy of steam than when the air did half the duty. But it was not only important to keep the air from flowing down the inside of the cylinder; the air which circulated within cooled the metal and condensed a portion of the steam within; and this Watt proposed to remedy by a second cylinder, surrounding the first, with an interval between the two which was to be kept full of steam.
One by one these various contrivances were struck out, modified, settled, and reduced to definite plans,—the separate condenser, the air and water pumps, the use of fat and oil (instead of water, as in the Newcomen engine) to keep the piston working in the cylinder air-tight, and the enclosing of the cylinder itself within another to prevent the loss of heat. These were all emanations from the first idea of inventing an engine working by a piston, in which the cylinder should be continually hot and perfectly dry. "When once," says Watt, "the idea of separate condensation was started, all these improvements followed as corollaries in quick succession, so that in the course of one or two days the invention was thus far complete in my mind."
The next step was to construct a model engine for the purpose of embodying the invention in a working form. With this object, Watt hired an old cellar, situated in the first wide entry to the north of the beef-market in King Street, and then proceeded with his model. He found itmuch easier, however, to prepare his plan than to execute it. Like most ingenious and inventive men, Watt was extremely fastidious; and this occasioned considerable delay in the execution of the work. His very inventiveness to some extent proved a hindrance; for new expedients were perpetually occurring to him, which he thought would be improvements, and which he, by turns, endeavored to introduce. Some of these expedients he admits proved fruitless, and all of them occasioned delay. Another of his chief difficulties was in finding competent workmen to execute his plans. He himself had been accustomed only to small metal work, with comparatively delicate tools, and had very little experience "in the practice of mechanicsin great" as he termed it. He was therefore under the necessity of depending, in a great measure, upon the handiwork of others. But mechanics capable of working out Watt's designs in metal were then with difficulty to be found. The beautiful self-action and workmanship which have since been called into being, principally by his own invention, did not then exist. The only available hands in Glasgow were the blacksmiths and tinners, little capable of constructing articles out of their ordinary walks; and even in these they were often found clumsy, blundering, and incompetent. The result was, that in consequence of the malconstruction of the larger parts, Watt's first model was only partially successful. The experiments made with it, however, served to verify the expectations he had formed, and to place the advantages of the invention beyond the reach of doubt. On the exhausting-cock being turned, the piston, when loaded with eighteen pounds, ascended as quickly as the blow of a hammer; and the moment the steam-cock was opened, it descended with like rapidity, thoughthe steam was weak, and the machine snifted at many openings.
Satisfied that he had laid hold of the right principle of a working steam-engine, Watt felt impelled to follow it to an issue. He could give his mind to no other business in peace until this was done. He wrote to a friend that he was quite barren on every other subject. "My whole thoughts," said he, "are bent on this machine. I can think of nothing else." He proceeded to make another and bigger, and, he hoped, a more satisfactory engine in the following August; and with that object he removed from the old cellar in King Street to a larger apartment in the then disused pottery, or delftwork, near the Broomielaw. There he shut himself up with his assistant, John Gardiner, for the purpose of erecting his engine. The cylinder was five or six inches in diameter, with a two-feet stroke. The inner cylinder was enclosed in a wooden steam-case, and placed inverted, the piston working through a hole in the bottom of the steam-case. After two months continuous application and labor it was finished and set to work; but it leaked in all directions, and the piston was far from air-tight. The condenser also was in a bad way, and needed many alterations. Nevertheless, the engine readily worked with ten and a half pounds pressure on the inch, and the piston lifted a weight of fourteen pounds. The improvement of the cylinder and piston continued Watt's chief difficulty, and taxed his ingenuity to the utmost. At so low an ebb was the art of making cylinders that the one he used was not bored, but hammered, the collective mechanical skill of Glasgow being then unequal to the boring of a cylinder of the simplest kind; nor, indeed, did the necessary appliances for the purpose then exist anywhere else. In the Newcomenengine a little water was found upon the upper surface of the piston, and sufficiently filled up the interstices between the piston and the cylinder. But when Watt employed steam to drive down the piston, he was deprived of this resource, for the water and steam could not coexist. Even if he had retained the agency of the air above, the drip of water from the crevices into the lower part of the cylinder would have been incompatible with keeping the cylinder hot and dry, and, by turning into vapor as it fell upon the heated metal, it would have impaired the vacuum during the descent of the piston.
While he was occupied with this difficulty, and striving to overcome it by the adoption of new expedients, such as leather collars and improved workmanship, he wrote to a friend, "My old white-iron man is dead;" the old white-iron man, or tinner, being his leading mechanic. Unhappily, also, just as he seemed to have got the engine into working order, the beam broke, and, having great difficulty in replacing the damaged part, the accident threatened, together with the loss of his best workman, to bring the experiment to an end. Though discouraged by these misadventures, he was far from defeated. But he went on as before, battling down difficulty inch by inch, and holding good the ground he had won, becoming every day more strongly convinced that he was in the right track, and that the important uses of the invention, could he but find time and means to perfect it, were beyond the reach of doubt. But how to find the means! Watt himself was a comparatively poor man; having no money but what he earned by his business of mechanical-instrument making, which he had for some time been neglecting through his devotion to the construction of his engine. What he wanted was capital, or the help of a capitalist willing to advancehim the necessary funds to perfect his invention. To give a fair trial to the new apparatus would involve an expenditure of several thousand pounds; and who on the spot could be expected to invest so large a sum in trying a machine so entirely new, depending for its success on physical principles very imperfectly understood?
There was no such help to be found in Glasgow. The tobacco lords,[10]though rich, took no interest in steam power; and the manufacturing class, though growing in importance, had full employment for their little capital in their own concerns.
"How Watt succeeded in interesting Dr. Roebuck in his project, and thus obtained funds to continue his experiments; how he finally joined with Matthew Boulton in the great firm of Boulton and Watt, manufacturers of steam-engines; how they pumped out all the water in the Cornish mines; and how Watt finally attained prosperity as well as success,—is an interesting story, but rather too long for these winter afternoons; and as the story of theinventionof the steam-engine is substantially told in the foregoing pages, we must stop our reading here, more especially as it seems to be tea-time, and I hear Ellen ringing the bell for supper."
They were to continue their talk and reading by following along the developments in the use of steam.
"Uncle Fritz," said Fanchon, "these agnostics make so much fun of our dear Harry and Lucy, that they will not let me quote from 'The Botanic Garden.'"
Emma promised that they would laugh as little as they could.
"'The Botanic Garden,'" said Fanchon, "was a stately, and I am afraid some of you would say very pompous, poem, written by Dr. Darwin."
"Dr. Darwin write poetry!"
"It is not the Dr. Charles Darwin whom you have heard of; it was his grandfather," said Uncle Fritz.
And Fanchon went on: "All I ever knew of 'The Botanic Garden' was in the quotations of our dear Harry and Lucy and Frank. But dear Uncle Fritz has taken down the book for me, and here it is, with its funny old pictures of Ladies' Slippers and such things."
"I do not see what Ladies' Slippers have to do with steam-engines," said Bedford Long, scornfully.
"No!" said Fanchon, laughing; "but I do, and that is the difference between you and me. Because, you see, I have read 'Harry and Lucy,' and you have not." Andshe opened "The Botanic Garden" at the place where she had put in a mark, and read:—
"Pressed by the ponderous air, the piston fallsResistless, sliding through its iron walls;Quick moves the balance beam of giant birth,Wields its large limbs, and nodding shakes the earth.The giant power, from earth's remotest cavesLifts, with strong arm, her dark reluctant waves,Each caverned rock and hidden depth explores,Drags her dark coals, and digs her shining ores."
"That is rather stilted poetry," said Uncle Fritz, "but a hundred years ago people were used to stilted poetry. It describes sufficiently well the original pumping-engine of Watt, and the lifting of coal from the shafts of the deep English mines. Now, it was not till Watt had made his improvements on the pumping-engine,—say in 1788,—that it was possible to go any farther in the use of steam than its application to such absolutely stationary purposes. It is therefore, I think, a good deal to the credit of Dr. Darwin, that within three years after Watt's great improvement in the condensing-engine the Doctor should have written this:—
'Soon shall thy arm, unconquered steam, afarDrag the slow barge or drive the rapid car.'
It was twelve years after he wrote this, that Fulton had an experimental steamboat on the river Seine in France. It was sixteen years after, that, with one of Watt's own engines, Fulton drove the 'Clermont' from New York to Albany in thirty-six hours, and revolutionized the world in doing it.
"Poor James Mackintosh was in virtual exile in Calcutta at that time, and he wrote this in his journal: 'A boatpropelled by steam has gone a hundred and fifty miles upon the Hudson in thirty-six hours. Four miles an hour would bring Calcutta within a hundred days of London. Oh that we had lived a hundred years later!' In less than fifty years after Mackintosh wrote those words, Calcutta was within thirty days of London.
"When Harry and Lucy read these verses in 1825, the 'rapid car' was still in the future."
"Yes," said Fanchon; "but Harry says, 'The rapid car is to come, and I dare say that will be accomplished soon, papa; do not you think it will?'"
"I have sometimes wondered," said Uncle Fritz, "whether our American word 'car' where the English say 'wagon' did not come from the 'rapid car' of Dr. Darwin. Read on, Fanchon." And he put his finger on the lines which Fanchon read:—
"Or on wide waving wings, expanded, bearThe flying chariot through the fields of air."
"Monsieur ——, the French gentleman, tried a light steam-engine for the propulsion of a balloon in 1872; but it does not seem to have had power enough. Messrs. Renard and Krebs, in their successful flight of August last, used an electric battery.
"But we are getting away from Fulton, who is really the first who drove the 'slow barge,' and indeed made it a very fast one."
"Did you know him?" asked Emma Fortinbras, whose ideas of chronology are very vague.
"Oh, no!" said Uncle Fritz; "he died young and before my time. But I did know a personal companion and friend, nay, a bedfellow of his, Benjamin Church, who was with him in Paris at one of the crises of his life. Fulton hada little steamboat on the river Seine, as I said just now; and he had made interest with Napoleon to have it examined by a scientific committee. Steam power was exactly what Napoleon wanted, to take his great army across from Boulogne to England. The day came for the great experiment. Church and Fulton slept, the night before, in the same bed in their humble lodgings in Paris. At daybreak a messenger waked them. He had come from the river to say that the weight of boiler and machinery had been too much for the little boat, that her timbers had given way, and that the whole had sunk to the bottom of the river. But for this misfortune, the successful steamboat would have sailed upon the Seine, and, for aught I know, Napoleon's grandchildren would now be emperors of England."
Until Watt had completed the structure of the double-acting condensing-engine, the application of steam to any but the single object of pumping water had been almost impracticable. It was not enough, in order to render it applicable to general purposes, that the condensation of the water should take place in a separate vessel, and that steam itself should be used, instead of atmospheric pressure, as the moving power; but it was also necessary that the steam should act as well during the ascent as during the descent of the piston. Before steam could be used in moving paddle-wheels, it was in addition necessary that a ready and convenient mode of making the motion of the piston continuous and rotary, should be discovered. All these improvements upon the original form of the steam-engine are due to Watt, and he did not complete their perfect combination before the year 1786.
Evans, who, in this country, saw the possibility of constructing a double-acting engine, even before Watt, andhad made a model of his machine, did not succeed in obtaining funds to make an experiment upon a large scale before 1801. We conceive, therefore, that all those who projected the application of steam to vessels before 1786, may be excluded, without ceremony, from the list of those entitled to compete with Fulton for the honors of invention. No one, indeed, could have seen the powerful action of a pumping-engine without being convinced that the energy which was applied so successfully to that single purpose, might be made applicable to many others; but those who entertained a belief that the original atmospheric engine, or even the single-acting engine of Watt, could be applied to propel boats by paddle-wheels, showed a total ignorance of mechanical principles. This is more particularly the case with all those whose projects bore the strongest resemblance to the plan which Fulton afterwards carried successfully into effect. Those who approached most nearly to the attainment of success, were they who were farthest removed from the plan of Fulton. His application was founded on the properties of Watt's double-acting engine, and could not have been used at all, until that instrument of universal application had received the last finish of its inventor.
In this list of failures, from proposing to do what the instrument they employed was incapable of performing, we do not hesitate to include Savery, Papin, Jonathan Hulls, Périer, the Marquis de Jouffroy, and all the other names of earlier date than 1786, whom the jealousy of the French and English nations have drawn from oblivion for the purpose of contesting the priority of Fulton's claims. The only competitor, whom they might have brought forward with some shadow of plausibility, is Watt himself. No sooner had that illustrious inventor completed his double-acting engine, than he saw at a glance the vast field of its application. Navigation and locomotion were not omitted; but living in an inland town, and in a country possessing no rivers of importance, his views were limited to canals alone. In this direction he saw an immediate objection to the use of any apparatus, of which so powerful an agent as his engine should be the mover; for it was clear, that the injury which would be done to the banks of the canal, would prevent the possibility of its introduction. Watt, therefore, after having conceived the idea of a steamboat, laid it aside, as unlikely to be of any practical value.
The idea of applying steam to navigation was not confined to Europe. Numerous Americans entertained hopes of attaining the same object, but, before 1786, with the same want of any reasonable hopes of success. Their fruitless projects were, however, rebuked by Franklin, who, reasoning upon the capabilities of the engine in its original form, did not hesitate to declare all their schemes impracticable; and the correctness of his judgment is at present unquestionable.
Among those who, before the completion of Watt's invention, attempted the structure of steamboats, must be named with praise Fitch and Rumsey. They, unlike those whose names have been cited, were well aware of the real difficulties which they were to overcome; and both were the authors of plans which, if the engine had been incapable of further improvement, might have had a partial and limited success. Fitch's trial was made in 1783, and Rumsey's in 1787. The latter date is subsequent to Watt's double-acting engine; but as the project consisted merely in pumping in water, to be afterwards forced out at the stern, the single-acting engine was probably employed. Evans, whose engine might have answered the purpose,was employed in the daily business of millwright; and although he might, at any time, have driven these competitors from the field, he took no steps to apply his dormant invention.
Fitch, who had watched the graceful and rapid way of the Indian canoe, saw in the oscillating motion of the old pumping-engine the means of impelling paddles in a manner similar to that given them by the human arm. This idea is extremely ingenious, and was applied in a simple and beautiful manner. But the engine was yet too feeble and cumbrous to yield an adequate force; and when it received its great improvement from Watt, a more efficient mode of propulsion had become practicable, and must have superseded Fitch's paddles had they even come into general use.
The experiments of Fitch and Rumsey in the United States, although generally considered unsuccessful, did not deter others from similar attempts. The great rivers and arms of the sea which intersect the Atlantic coast, and, still more, the innumerable navigable arms of the Father of Waters, appeared to call upon the ingenious machinist to contrive means for their more convenient navigation.
The improvement of the engine by Watt was now familiarly known; and it was evident that it possessed sufficient powers for the purpose. The only difficulty which existed, was in the mode of applying it. The first person who entered into the inquiry was John Stevens, of Hokoken, who commenced his researches in 1791. In these he was steadily engaged for nine years, when he became the associate of Chancellor Livingston and Nicholas Roosevelt. Among the persons employed by this association was Brunel, who has since become distinguished in Europe as the inventor of the block machinery used in the Britishnavy-yards, and as the engineer of the tunnel beneath the Thames.
Even with the aid of such talent, the efforts of this association were unsuccessful,—as we now know, from no error in principle, but from defects in the boat to which it was applied. The appointment of Livingston as ambassador to France broke up this joint effort; and, like all previous schemes, it was considered abortive, and contributed to throw discredit upon all undertakings of the kind. A grant of exclusive privileges on the waters of the State of New York was made to this association without any difficulty, it being believed that the scheme was little short of madness.
Livingston, on his arrival in France, found Fulton domiciliated with Joel Barlow. The conformity in their pursuits led to intimacy, and Fulton speedily communicated to Livingston the scheme[11]which he had laid before Earl Stanhope in 1793. Livingston was so well pleased with it that he at once offered to provide the funds necessary for an experiment, and to enter into a contract for Fulton's aid in introducing the method into the United States, provided the experiment were successful.
Fulton had, in his early discussion with Lord Stanhope, repudiated the idea of an apparatus acting on the principle of the foot of an aquatic bird, and had proposed paddle-wheels in its stead. On resuming his inquiries after his arrangements with Livingston, it occurred to him to compose wheels with a set of paddles revolving upon anendless chain extending from the stem to the stern of the boat. It is probable that the apparent want of success which had attended the experiments of Symington[12]led him to doubt the correctness of his original views.
That such doubt should be entirely removed, he had recourse to a series of experiments upon a small scale. These were performed at Plombières, a French watering-place, where he spent the summer of 1802. In these experiments the superiority of the paddle-wheel over every other method of propulsion that had yet been proposed, was fully established. His original impressions being thus confirmed, he proceeded, late in the year 1803, to construct a working model of his intended boat, which model was deposited with a commission of Frenchsavans. He at the same time began building a vessel sixty-six feet in length and eight feet in width. To this an engine was adapted; and the experiment made with it was so satisfactory, as to leave little doubt of final success.
Measures were therefore immediately taken, preparatory to constructing a steamboat on a larger scale in the United States. For this purpose, as the workshops of neither France nor America could at that time furnish an engine of good quality, it became necessary to resort to England for that purpose. Fulton had already experienced the difficulty of being compelled to employ artists unacquainted with the subject. It is, indeed, more than probable, that, had he not, during his residence in Birmingham, made himself familiar, not only with the general features, but with the most minute details of the engine of Watt, the experiment on the Seine could not have beenmade. In this experiment, and in the previous investigations, it became obvious that the engine of Watt required important modifications in order to adapt it to navigation. These modifications had been planned by Fulton; but it now became important, that they should be more fully tested. An engine was therefore ordered from Watt and Boulton, without any specification of the object to which it was to be applied; and its form was directed to be varied from their usual models, in conformity to sketches furnished by Fulton.
The order for an engine intended to propel a vessel of large size, was transmitted to Watt and Boulton in 1803. At about the same time, Chancellor Livingston, having full confidence in the success of the enterprise, caused an application to be made to the legislature of New York for an exclusive privilege of navigating the waters of that State by steam, that which was granted on a former occasion having expired.
This privilege was granted with little opposition. Indeed, those who might have been inclined to object, saw so much of the impracticable and even of the ridiculous in the project, that they conceived the application unworthy of serious debate. The condition attached to the grant was, that a vessel should be propelled by steam at the rate of four miles an hour, within a prescribed space of time. This reliance upon the reserved rights of the States proved a fruitful source of vexation to Livingston and Fulton, and imbittered the close of the life of the latter, and reduced his family to penury. It can hardly be doubted that, had an expectation been entertained, that the grant of a State was ineffectual, and that the jurisdiction was vested in the general government, a similar grant might have been obtained from Congress. The influence of Livingston withthe administration was deservedly high, and that administration was supported by a powerful majority; nor would it have been consistent with the principles of the opposition to vote against any act of liberality to the introducer of a valuable application of science. Livingston, however, confiding in his skill as a lawyer, preferred the application to the State, and was thus, by his own act, restricted to a limited field.
Before the engine ordered from Watt and Boulton was completed, Fulton visited England, and thus had an opportunity of visiting Birmingham, and directing, in person, its construction. It could only have been at this time, if ever, that he saw the boat of Symington;[13]but a view of it could have produced no effect upon his own plans, which had been matured in France, and carried, so far as the engine was concerned, to such an extent as to admit of no alteration.
The engine was at last completed, and reached New York in 1806. Fulton, who returned to his native country about the same period, immediately undertook the construction of a boat in which to place it. In ordering his engine and in planning the boat, Fulton exhibited plainly how far his scientific researches and practical experiments had placed him before all his competitors. He had evidently ascertained, what each successive year's experience proves more fully, the great advantages possessed by large steamboats over those of smaller size; and thus, while all previous attempts had been made in smaller vessels, he alone resolved to make his final experiment in one of great dimensions. That a vessel,intended to be propelled by steam, ought to have very different proportions, and lines of a character wholly distinct from those of vessels intended to be navigated by sails, was evident to him. No other theory, however, of the resistance of fluids was admitted at the time than that of Bossut, and there were no published experiments except those of the British Society of Arts. Judged in reference to these, the model chosen by Fulton was faultless, although it will not stand the test of an examination founded upon a better theory and more accurate experiments.
The vessel was finished and fitted with her machinery in August, 1807. An experimental excursion was forthwith made, at which a number of gentlemen of science and intelligence were present. Many of these were either sceptical or absolute unbelievers. But a few minutes served to convert the whole party, and satisfy the most obstinate doubters, that the long-desired object was at last accomplished. Only a few weeks before, the cost of constructing and finishing the vessel threatening to exceed the funds with which he had been provided by Livingston, Fulton had attempted to obtain a supply by the sale of one third of the exclusive right granted by the State of New York. No person was found possessed of the faith requisite to induce him to embark in the project. Those who had rejected this opportunity of investment, were now the witnesses of the completion of the scheme, which they had considered as an inadequate security for the desired funds.
Within a few days from the time of the first experiment with the steamboat, a voyage was undertaken in it to Albany. This city, situated at the natural head of the navigation of the Hudson, is distant, by the line of thechannel of the river, rather less than one hundred and fifty miles from New York. By the old post-road, the distance is one hundred and sixty miles, at which that by water is usually estimated. Although the greater part of the channel of the Hudson is both deep and wide, yet for about fourteen miles below Albany this character is not preserved, and the stream, confined within comparatively small limits, is obstructed by bars of sand or spreads itself over shallows. In a few remarkable instances, the sloops, which then exclusively navigated the Hudson, had effected a passage in about sixteen hours; but a whole week was not unfrequently employed in the voyage, and the average time of passage was not less than four entire days. In Fulton's first attempt to navigate this stream, the passage to Albany was performed in thirty-two hours, and the return in thirty.
Up to this time, although the exclusive grant had been sought and obtained from the State of New York, it does not appear that either he or his associate had been fully aware of the vast opening which the navigation of the Hudson presented for the use of steam. They looked to the rapid Mississippi and its branches, as the place where their triumph was to be achieved; and the original boat, modelled for shallow waters, was announced as intended for the navigation of that river. But even in the very first attempt, numbers, called by business or pleasure to the northern or western parts of the State of New York, crowded into the yet untried vessel; and when the success of the attempt was beyond question, no little anxiety was manifested, that the steamboat should be established as a regular packet between New York and Albany.
With these indications of public feeling Fulton immediately complied, and regular voyages were made at statedtimes until the end of the season. These voyages were not, however, unattended with inconvenience. The boat, designed for a mere experiment, was incommodious; and many of the minor arrangements by which facility of working and safety from accident to the machinery were to be insured, were yet wanting. Fulton continued a close and attentive observer of the performance of the vessel; every difficulty, as it manifested itself, was met and removed by the most masterly as well as simple contrivances. Some of these were at once adopted, while others remained to be applied while the boat should be laid up for the winter. He thus gradually formed in his mind the idea of a complete and perfect vessel; and in his plan, no one part which has since been found to be essential to the ease of manœuvre or security, was omitted. But the eyes of the whole community were now fixed upon the steamboat; and as all those of competent mechanical knowledge were, like Fulton himself, alive to the defects of the original vessel, his right to priority of invention of various important accessories has been disputed.
The winter of 1807-8 was occupied in remodelling and rebuilding the vessel, to which the name "Clermont" was now given. The guards and housings for the wheels, which had been but temporary structures, applied as their value was pointed out by experience, became solid and essential parts of the boat. For a rudder of the ordinary form, one of surface much more extended in its horizontal dimensions was substituted. This, instead of being moved by a tiller, was acted upon by ropes applied to its extremity; and these ropes were adapted to a steering-wheel, which was raised aloft towards the bow of the vessel.
It had been shown by the numbers who were transported during the first summer, that at the same price forpassage, many were willing to undergo all the inconveniences of the original rude accommodations, in preference to encountering the delays and uncertainty to which the passage in sloops was exposed. Fulton did not, however, take advantage of his monopoly, but with the most liberal spirit, provided such accommodations for passengers, as in convenience and even splendor, had not before been approached in vessels intended for the transportation of travellers. This was, on his part, an exercise of almost improvident liberality. By his contract with Chancellor Livingston, the latter undertook to defray the whole cost of the engine and vessel, until the experiment should result in success; but from that hour each was to furnish an equal share of all investments. Fulton had no patrimonial fortune, and what little he had saved from the product of his ingenuity was now exhausted. But the success of the experiment had inspired the banks and capitalists with confidence, and he now found no difficulty in obtaining, in the way of loan, all that was needed. Still, however, a debt was thus contracted which the continued demands made upon him for new investments never permitted him to discharge. The "Clermont," thus converted into a floating palace, gay with ornamental painting, gilding, and polished woods, began her course of passages for the second year in the month of April.
The first voyage of this year was of the most discouraging character. Chancellor Livingston, who had, by his own experiments, approached as near to success as any other person who, before Fulton, had endeavored to navigate by steam, and who had furnished all the capital necessary for the experiment, had plans and projects of his own. These he urged into execution in spite of theopposition of Fulton. The boiler furnished by Watt and Boulton was not adapted to the object. Copied from those used on the land, it required that its fireplace and flues should be constructed of masonry. These added so much weight to the apparatus, that the rebuilt boat would hardly have floated had they been retained. In order to replace this boiler, Livingston had planned a compound structure of wood and copper, which he insisted should be tried.
It is only necessary for us to say, that this boiler proved a complete failure. Steam began to issue from its joints a few hours after the "Clermont" left New York. It then became impossible to keep up a proper degree of tension, and the passage was thus prolonged to forty-eight hours. These defects increased after leaving Albany on the return, and the boiler finally gave way altogether within a few miles of New York. The time of the downward passage was thus extended to fifty-six hours. Fulton was, however, thus relieved from all further interference; this fruitless experiment was decisive as to his superiority over his colleague in mechanical skill. He therefore immediately planned and directed the execution of a new boiler, which answered the purpose perfectly; and although there are many reasons why boilers of a totally different form and of subsequent invention should be preferred, it is, for its many good properties, extensively used, with little alteration, up to the present day. But a few weeks sufficed to build and set this boiler, and in the month of June the regular passages of the "Clermont" were renewed.
In observing the hour appointed for departure, both from New York and Albany, Fulton determined to insist upon the utmost regularity. It required no little perseverance and resolution to carry this system of punctualityinto effect. Persons accustomed to be waited for by packet-boats and stages, assented with great reluctance to what they conceived to be a useless adherence to precision of time. The benefits of this punctuality were speedily perceptible; the whole system of internal communication of the State of New York was soon regulated by the hours of arrival and departure of Fulton's steamboats; and the same system of precision was copied in all other steamboat lines. The certainty of conveyance at stated times being thus secured, the number of travellers was instantly augmented; and before the end of the second summer, the boat became far too small for the passengers, who crowded to avail themselves of this novel, punctual, and unprecedentedly rapid method of transport.
Such success, however, was not without its alloy. The citizens of Albany and the river towns saw, as they thought, in the steamboat, the means of enticing their customers from their ancient marts to the more extensive market of the chief city; the skippers of the river mourned the inevitable loss of a valuable part of their business; and innumerable projectors beheld with envy the successful enterprise of Fulton.
Among the latter class was one who, misled by false notions of mechanical principles, fancied that in the mere oscillations of a pendulum lay a power sufficient for any purpose whatever. Availing himself of a well-constructed model, he exhibited to the inhabitants of Albany a pendulum which continued its motions for a considerable time, without requiring any new impulse, and at the same time propelled a pair of wheels. These wheels, however, did not work in water. Those persons who felt themselves aggrieved by the introduction of steamboats, quickly embraced this project, prompted by an enmity to Fulton,and determined, if they could not defeat his object, at least to share in the profits of its success.
It soon appeared, from preliminary experiments, made in a sloop purchased for the purpose, that a steam-engine would be required to give motion to the pendulum; and it was observed that the water-wheels, when in connection with the pendulum, had a very irregular motion. A fly-wheel was therefore added, and the pendulum was now found to be a useless incumbrance. Enlightened by these experiments, the association proceeded to build two boats; and these were exact copies, not only of the hull and all the accessories of the "Clermont," but the engine turned out to be identical in form and structure with one which Fulton was at the very time engaged in fitting to his second boat, "The Car of Neptune."
The pretence of bringing into use a new description of prime mover was of course necessarily abandoned, and the owners of the new steamboats determined boldly to test the constitutionality of the exclusive grant to Fulton. Fulton and Livingston, in consequence, applied to the Court of Chancery of the State of New York for an injunction, which was refused. On an appeal to the Court of Errors this decision of the Chancellor was reversed; but the whole of the profits which might have been derived from the business of the year were prevented from accruing to Livingston and Fulton, who, compelled to contend in price with an opposition supported by popular feeling in Albany, were losers rather than gainers by the operations of the season.
As no appeal was taken from this last decision, the waters of the State of New York remained in the exclusive possession of Fulton and his partner, until the death of the former. This exclusive possession was not, however,attended with all the advantages that might have been anticipated. The immense increase of travel which the facilities of communication created, rendered it imperative upon the holders of the monopoly to provide new facilities by the construction of new vessels. The cost of these could not be defrayed out of the profits. Hence new and heavy debts were necessarily contracted by Fulton, while Livingston, possessed of an ample fortune, required no pecuniary aid beyond what he was able to meet from his own resources.
The most formidable opposition which was made to the privileges of Fulton, was founded upon the discoveries of Fitch. We have seen, that he constructed a boat which made some passages between Trenton and Philadelphia; but the method which he used, was that of paddles, which are far inferior to the paddle-wheel. Of the inferiority of the method of paddles, had any doubt remained, positive evidence was afforded in the progress of this dispute; for in order to bring the question to the test of a legal decision, a boat propelled by them was brought into the waters of the State of New York. The result of the experiment was so decisive, that when the parties engaged in the enterprise had succeeded in their designs, they made no attempt to propel their boats by any other method than that of wheels.
Fulton, assailed in his exclusive privileges derived from State grants, took, for his further protection, a patent from the general government. This is dated in 1809, and was followed by another, for improvements upon it, in 1811. It now appeared, that the very circumstance in which the greatest merit of his method consists, was to be the obstacle to his maintaining an exclusive privilege. Discarding all complexity, he had limited himself to the simple meansof adapting paddle-wheels to the crank of Watt's engine; and, under the patent laws, it seems hardly possible that such a simple yet effectual method could be guarded by a specification. As has been the case with many other important discoveries, the most ignorant conceived that they might themselves have discovered it; and those unacquainted with the history of the attempts at navigation by steam, were compelled to wonder that it had been left for Fulton to bring it into successful operation.
Before the death of Fulton, the steamboats on the Hudson River were increased in number to five. A sixth was built under his direction for the navigation of the Sound; and, this water being rendered unsafe by the presence of an enemy's[14]squadron, the boat plied for a time upon the Hudson. In the construction of this boat he had, in his own opinion, exhausted the power of steam in navigation, having given it a speed of nine miles an hour; and it is a remarkable fact, which manifests his acquaintance with theory and skill in calculation, that he in all cases predicted with almost absolute accuracy, the velocity of the vessels he caused to be constructed. The engineers of Great Britain came, long after, to a similar conclusion in respect to the maximum of speed.
It is now, however, well known, that, with a proper construction of prows, the resistance to vessels moving at higher velocities than nine miles an hour, increases in a much less ratio than had been inferred from experiments made upon wedge-shaped bodies; and that the velocity of the pistons of steam-engines may be conveniently increased beyond the limit fixed by the practice of Watt.
For these important discoveries the world is indebtedprincipally to Robert L. Stevens. That Fulton must have reached them in the course of his own practice can hardly be doubted, had his valuable life been spared to watch the performance of the vessels he was engaged in building at the time of his premature death.[15]These were, a large boat intended for the navigation of the Hudson, to which the name of his partner, Chancellor Livingston, was given, and one planned for the navigation of the ocean. The latter was constructed with the intention of making a passage to St. Petersburg; but this scheme was interrupted by his death, which took place at the moment he was about to add to his glory, as the first constructor of a successful steamboat, that of being the first navigator of the ocean by this new and mighty agent.
"What I say is this," said Nahum, "that all your Vesuvius dividends, and all your pickers and slobbers, and shirtings at four cents, and all the rest of your great cotton victory, depend on railroads. If your father could not go to Lewiston and see his foreman and people, and come back before you can say Jack Robinson, there would be no mills at Lewiston such as there are. There might be a poor little sawmill making shingles, as you free-traders want." This with scorn at Fergus, perhaps, or some one else suspected of views unfavorable to protection.
Then Nahum shook hands with Uncle Fritz, and apologized for his zeal, adding: "I am telling the boys why I want to go to Altoona, and to become a railroad man. I say that the new plant in India might knock cotton higher than a kite, and that people might learn to live without novels or magazines, but that they must have transportation all the same. And I am going into the railroad business. I am going to hew down the mountains and fill up the valleys." The boy was fairly eloquent in his enthusiasm.
"It is in your blood, my brave fellow," said Uncle Fritz. "People thought your grandfather was crazy whenhe said it, sixty years ago. But it proved he was the seer and the prophet, and they were the fools."
"And who invented railroads?" asked Blanche.
"As to that, the man invented a railroad who first put two boards down over two ruts to make a cart run easier. Almost as soon as there were mines, there must have been some sort of rail for the use of the wagons which brought out the ore. These rails became so useful that they were continued from the mine to the high-road, whatever it was. But it was not till the first quarter of this century, that rails were laid for general use. The earliest railroad in the United States was laid at the quarries in Quincy, in Massachusetts, in 1825."
Uncle Fritz was so well pleased at their eagerness that he brought out for them some of the old books, and some of the new. In especial he bade them all read Smiles's "Life of Stephenson" before they came to him again. For to George Stephenson, as they soon learned, more than to any one man, the world owes the step forward which it made when locomotives were generally used on railroads. Since that time the improvements in both have gone on together.
Before they met again, at Uncle Fritz's suggestion, Fergus and Hester prepared this sketch of the details of Stephenson's earlier invention, purposely that Uncle Fritz might use it when these papers should be printed together.
An efficient and economical working locomotive engine still remained to be invented, and to accomplish this object Stephenson now applied himself. Profiting by what his predecessors had done,—warned by their failures andencouraged by their partial successes,—he began his labors. There was still wanting the man who should accomplish for the locomotive what James Watt had done for the steam-engine, and combine in a complete form the best points in the separate plans of others, embodying with them such original inventions and adaptations of his own, as to entitle him to the merit of inventing the working locomotive, as James Watt is to be regarded as the inventor of the working condensing-engine. This was the great work upon which George Stephenson now entered, though probably without any adequate idea of the ultimate importance of his work to society and civilization.
He proceeded to bring the subject of constructing a "Travelling Engine," as he denominated the locomotive, under the notice of the lessees of the Killingworth Colliery,[16]in the year 1813. Lord Ravensworth, the principal partner, had already formed a very favorable opinion of the new colliery engine-wright from the improvements which he had effected in the colliery engines, both above and below ground; and after considering the matter, and hearing Stephenson's explanations, he authorized him to proceed with the construction of a locomotive, though his lordship was by some called a fool for advancing money for such a purpose. "The first locomotive that I made," said Stephenson, many years after, when speaking of his early career at a public meeting in Newcastle, "was at Killingworth Colliery, and with Lord Ravensworth's money. Yes, Lord Ravensworth and partners were the first to intrust me, thirty-two years since, with money to make a locomotive engine. I said to my friends, there was no limit to the speed of such an engine, if the works could be made to stand."
Our engine-wright had, however, many obstacles to encounter before he could get fairly to work upon the erection of his locomotive. His chief difficulty was in finding workmen sufficiently skilled in mechanics and in the use of tools to follow his instructions, and embody his designs in a practical shape. The tools then in use about the colliery were rude and clumsy, and there were no such facilities, as now exist, for turning out machinery of any entirely new character. Stephenson was under the necessity of working with such men and tools as were at his command, and he had in a great measure to train and instruct the workmen himself. The new engine was built in the workshops at the West Morr, the leading mechanic being John Thirlwall, the colliery blacksmith,—an excellent mechanic in his way, though quite new to the work now intrusted to him.
In this first locomotive, constructed at Killingworth, Stephenson to some extent followed the plan of Blenkinsop's engine. The wrought-iron boiler was cylindrical, eight feet in length and thirty-four inches in diameter, with an internal flue-tube twenty inches wide passing through it. The engine had two vertical cylinders, of eight inches diameter and two feet stroke, let into the boiler, which worked the propelling gear with cross-heads and connecting-rods. The power of the two cylinders was combined by means of spur-wheels, which communicated the motive power to the wheels supporting theengine on the rail. The engine thus worked upon what is termed the second motion. The chimney was of wrought-iron, round which was a chamber extending back to the feed-pumps, for the purpose of heating the water previous to its injection into the boiler. The engine had no springs, and was mounted on a wooden frame supported on four wheels. In order to neutralize as much as possible the jolts and shocks which such an engine would necessarily encounter, from the obstacles and inequalities of the then very imperfect plate-way, the water-barrel, which served for a tender, was fixed to the end of a lever and weighted; the other end of the lever being connected with the frame of the locomotive carriage. By this means the weight of the two was more equally distributed, though the contrivance did not by any means compensate for the total absence of springs.
The wheels of the locomotive were all smooth, Stephenson having satisfied himself by experiment that the adhesion between the wheels of a loaded engine and the rail would be sufficient for the purposes of traction.[17]
The engine was, after much labor and anxiety, and frequent alterations of parts, at length brought to completion, having been about ten months in hand. It was placed upon the Killingworth Railway on the 25th of July, 1814, and its powers were tried on the same day. On an ascending gradient of 1 in 450, the engine succeeded in drawing after it eight loaded carriages, of thirty tons weight, at about four miles an hour; and for some time after it continued regularly at work.
Although a considerable advance upon previous locomotives, "Blucher" (as the engine was popularly called) was nevertheless a somewhat cumbrous and clumsy machine. The parts were huddled together. The boiler constituted the principal feature; and, being the foundation of the other parts, it was made to do duty not only as a generator of steam, but also as a basis for the fixings of the machinery and for the bearings of the wheels and axles. The want of springs was seriously felt; and the progress of the engine was a succession of jolts, causing considerable derangement to the working. The mode of communicating the motive power to the wheels by means of the spur-gear also caused frequent jerks, each cylinder alternately propelling or becoming propelled by the other, as the pressure of the one upon the wheels became greater or less than the pressure of the other; and when the teeth of the cog-wheels became at all worn, a rattling noise was produced during the travelling of the engine.
As the principal test of the success of the locomotive was its economy as compared with horse-power, careful calculations were made with the view of ascertaining this important point. The result was, that it was found the working of the engine was at first barely economical; and at the end of the year the steam-power and the horse-power were ascertained to be as nearly as possible upon a par in point of cost.
We give the remainder of the history of George Stephenson's efforts to produce an economical working locomotive in the words of his son Robert, as communicated to Mr. Smiles in 1856, for the purposes of his father's "Life."
"A few months of experience and careful observation upon the operation of this (his first) engine convinced my father that the complication arising out of the actionof the two cylinders being combined by spur-wheels would prevent their coming into practical application. He then directed his attention to an entire change in the construction and mechanical arrangements, and in the following year took out a patent, dated Feb. 28, 1815, for an engine which combined in a remarkable degree the essential requisites of an economical locomotive,—that is to say, few parts, simplicity in their action, and great simplicity in the mode by which power was communicated to the wheels supporting the engine.
"This second engine consisted, as before, of two vertical cylinders; which communicated directly with each pair of the four wheels that supported the engine by a cross-head and a pair of connecting-rods. But in attempting to establish a direct communication between the cylinders and the wheels that rolled upon the rails, considerable difficulties presented themselves. The ordinary joints could not be employed to unite the engine, which was a rigid mass, with the wheels rolling upon the irregular surface of the rails; for it was evident that the two rails of the line of railway could not always be maintained at the same level with respect to each other,—that one wheel at the end of the axle might be depressed into a part of the line which had subsided, while the other would be elevated. In such a position of the axle and wheels it was clear that a rigid communication between the cross-head and the wheels was impracticable. Hence it became necessary to form a joint at the top of the piston-rod where it united with the cross-head, so as to permit the cross-head always to preserve complete parallelism with the axle of the wheels with which it was in communication.
"In order to obtain the flexibility combined with direct action, which was essential for insuring power andavoiding needless friction and jars from irregularities in the rail, my father employed the 'ball and socket joint' for effecting a union between the ends of the cross-heads, where they were united with the crank-pins attached to each driving-wheel. By this arrangement the parallelism between the cross-head and the axle was at all times maintained, it being permitted to take place without producing jar or friction upon any part of the machine.
"The next important point was to combine each pair of wheels by some simple mechanism, instead of the cog-wheels which had formerly been used. My father began by inserting each axle into two cranks, at right angles to each other, with rods communicating horizontally between them. An engine was made upon this plan, and answered extremely well. But at that period (1815) the mechanical skill of the country was not equal to the task of forging cranked axles of the soundness and strength necessary to stand the jars incident to locomotive work; so my father was compelled to fall back upon a substitute which, though less simple and less efficient, was within the mechanical capabilities of the workmen of that day, either for construction or repair. He adopted a chain, which rolled over indented wheels placed on the centre of each axle, and so arranged that the two pairs of wheels were effectually coupled and made to keep pace with each other. But these chains after a few years' use became stretched, and then the engines were liable to irregularity in their working, especially in changing from working back to forward again. Nevertheless, these engines continued in profitable use upon the Killingworth Colliery Railway for some years. Eventually the chain was laid aside, and the wheels were united by rods on theoutsideinstead of rods and crank-axles inside, as specified in theoriginal patent; and this expedient completely answered the purpose required, without involving any expensive or difficult workmanship.
"Another important improvement was introduced in this engine. The eduction steam had hitherto been allowed to escape direct into the open atmosphere; but my father having observed the great velocity with which the smoke issued from the chimney of the same engine, thought that by conveying the eduction steam into the chimney, and there allowing it to escape in a vertical direction, its velocity would be imparted to the smoke from the engine, or to the ascending current of air in the chimney. The experiment was no sooner made than the power of the engine became more than doubled; combustion was stimulated, as it were, by a blast; consequently, the power of the boiler for generating steam was increased, and in the same proportion, the useful duty of the engine was augmented.
"Thus, in 1815 my father had succeeded in manufacturing an engine which included the following important improvements on all previous attempts in the same direction: simple and direct communication between the cylinder and the wheels rolling upon the rails; joint adhesion of all the wheels, attained by the use of horizontal connecting-rods; and, finally, a beautiful method of exciting the combustion of fuel by employing the waste steam which had formerly been allowed to escape uselessly. It is perhaps not too much to say that this engine, as a mechanical contrivance, contained the germ of all that has since been effected. It may be regarded, in fact, as a type of the present locomotive engine.
"In describing my father's application of the waste steam for the purpose of increasing the intensity of combustion in the boiler, and thus increasing the power of the engine without adding to its weight, and while claiming for this engine the merit of being a type of all those which have been successfully devised since the commencement of the Liverpool and Manchester Railway, it is necessary to observe that the next great improvement in the same direction, the 'multitubular boiler,' which took place some years later, could never have been used without the help of that simple expedient,the steam-blast, by which power only, the burning of coke was rendered possible.
"I cannot pass over this last-named invention of my father's without remarking how slightly, as an original idea, it has been appreciated; and yet how small would be the comparative value of the locomotive engine of the present day, without the application of that important invention.
"Engines constructed by my father in the year 1818, upon the principles just described, are in use on the Killingworth Colliery Railway to this very day (1856), conveying, at the speed of perhaps five or six miles an hour, heavy coal-trains, probably as economically as any of the more perfect engines now in use."
The invention of the steam-blast by George Stephenson in 1815 was fraught with the most important consequences to railway locomotion; and it is not saying too much to aver that the success of the locomotive has been in a great measure the result of its adoption. Without the steam-blast, by means of which the intensity of combustion is maintained at its highest point, producing a correspondingly rapid evolution of steam, high rates of speed could not have been kept up; the advantages of the multitubular boiler (afterward invented) could never havebeen fully tested; and locomotives might still have been dragging themselves unwieldily along at a rate of a little more than five or six miles an hour.
As the period drew near for the opening of the line, the question of the tractive power to be employed was anxiously discussed. At the Brusselton decline, fixed engines must necessarily be made use of; but with respect to the mode of working the railway generally, it was decided that horses were to be largely employed, and arrangements were made for their purchase.
Although locomotives had been regularly employed in hauling coal-wagons on the Middleton Colliery Railway, near Leeds, for more than twelve years, and on the Wylam and Killingworth Railways, near Newcastle, for more than ten years, great scepticism still prevailed as to the economy of employing them for the purpose in lieu of horses. In this case, it would appear that seeing wasnotbelieving. The popular scepticism was as great at Newcastle, where the opportunities for accurate observation were the greatest, as anywhere else. In 1824 the scheme of a canal between that town and Carlisle again came up; and although a few timid voices were raised on behalf of a railway, the general opinion was still in favor of a canal. The example of the Hetton Railway, which had been successfully worked by Stephenson's locomotives for two years past, was pointed to in proof of the practicability of a locomotive line between the two places; but the voice of the press, as well as of the public, was decidedly against the "new-fangled roads."