“I cannot now leave Wheal Virgin a single day,” wrote Watt, “without running the risk of some vile blunder, particularly as the boilers are now setting. Wm. Murdock was at Wheal Virgin one day this week, and that day was taken up with Mr. Wedgwood,[238] so that it was partly lost. Yesterday he was taken away by Crenver people and is not returned. I fear I cannot get much of his help, and I assure you I need it much, for there cannot be a greater plague than to have five engines making by ignorant men and no helpmate to look after them. I have been tolerably well these few days, but cannot get up my spirits, from having too much to think upon.”
Combined with the troubles arising out of the perversities, blunderings, and bad conduct of his workmen, Watt had also to struggle against torment of mind and body, aggravated by bad news from home. Boulton was in the crisis of his troubles with his partner Fothergill, from which he was desperately struggling to shake himself free.[239]
Watt was made additionally miserable by the state of the bankers’ account, which was still overdrawn to a very large amount. The bankers were urgent for repayment, but neither of the partners saw where the money was to come from. Watt again thought of giving up altogether, and selling his share of the business as the only means of relief which presented itself.
“I am almost moved,” he wrote, “if Lowe, Vere, and Williams will free me from any demands on my future industry, to give up my present property altogether, and trust to Providence for my support. I cannot live as I am with any degree of comfort. The want of the superfluities of life is a trifle compared with continual anxiety. I do not see how you can pay L. V. & W. 1000l. per quarter; I am sure it cannot be from the engine business, unless we can reduce the amount of our general expenses to 0 and live upon air ourselves.... Though you and I should entirely lose this business and all its profits, you will get quit of a burdensome debt; and as both of us lived before it had a being, so we may do afterwards. Therefore consider what can be done, and do it without reluctance, or with as little as you can; and depend upon it that I am sincerely your friend, and shall push you to nothing that I do not think to be for your advantage.”[240]
Two days later, while still in a heavily desponding humour, he wrote thus:—
“If matters were to come to the worst, many methods may be fallen upon whereby we may preserve some consequence in the world. A hundred hours of melancholy will not pay one farthing of debt. Summon up your fortitude and try to turn your attention to business, and to correct the abuses at Soho.... All the idlers should be told that in case they persevere in want of attention, then dismission must ensue.... The Soho part of the business has been somehow a perpetual drain to us, and if it cannot be put on a better footing, must be cut off altogether by giving out the work to be done by others.”[241]
To add to their troubles, a fire broke out in the house of Boulton and Watt’s London agent for the sale of their copying machines, and the building, with its contents, was burnt to the ground, thereby causing a loss to the firm of above a thousand pounds. The mining trade was also wretchedly bad in Cornwall, several of the more important mines being unproductive, while ore was selling at low prices. The adventurers were accordingly urging Watt to abate the agreed dues for the use of their engines, and in several cases threatened to close the mines unless he did so. The United Mines asked to be reduced 50l. a month. Watt having refused to make the abatement, the mine was ordered to be stopped, on which he consented to give up the dues altogether for a period of six months. “There seemed,” he wrote to Boulton, “to be no other course, if we would maintain our right, and at the same time do justice to the poor people, who must otherwise absolutely starve, and are already riotously disposed through the stopping of Wheal Virgin.”[242] “In short,” said he, “almost the whole county is against us, and look upon us as oppressors and tyrants, from whose power they believe the horned imps of Satan are to relieve them.” Watt was indeed thoroughly sick of Cornwall, and longed to get back to Birmingham. He confessed he did not see how, under the present state of things, he could be of any more use there. The weather was very tempestuous, and he felt the fatigue of travelling from mine to mine too much for him to endure. On the 4th of April he wrote,—“I returned from the coast to Cosgarne last night with an aching head, after a peregrination of two days in very stormy weather.” “Upon the whole,” he wrote to Boulton, “I look upon our present Cornish prospects as very bad, and would not have you build too much upon them nor upon the engine business, without some material change. I shall think it prudent to look out for some other way of livelihood, as I expect that this will be swallowed up in merely paying its burdens.”[243] Watt, accordingly, finding that he could do no more good in Cornwall, left it about the middle of April, and returned with an aching head and heavy heart to Birmingham.
CHAPTER XVI.
More Difficulties and more Inventions—Boulton again
in Cornwall.
The battle of the firm had hitherto been all up-hill. Nearly twenty years had passed since Watt had made his invention. His life since then had been a constant struggle, and it was a struggle still. Thirteen years had passed since the original patent had been taken out, and seven since the Act had been passed for its extension. But the engine had as yet yielded no profit, and the outlay of capital continued. Notwithstanding Boulton’s energy and resources, the partners were often in the greatest straits for money, and sometimes, as Saturday nights came round, they had to beat about among their friends for the means of paying the workmen’s wages.
Though Watt continued to imagine himself on the brink of ruin, things were not really so gloomy as he supposed. We find Boulton stating in a confidential letter to Matthews, that the dues payable on the pumping-engines actually erected in 1782 amounted to 4320l. a year; and that when all the engines in progress had been finished, they would probably amount to about 9000l. It is true, the dues were paid with difficulty by the mining interest, still in a state of great depression, but Boulton looked forward with confidence to better days coming round. Indeed, he already saw his way through the difficulties of the firm, and encouraged his doleful partner to hope that in the course of a very few years more, they would be rid of their burdens.
As Cornwall was, however, now becoming well supplied with pumping-engines, it became necessary to open up new branches of business to keep the Soho manufactory in full work. With this object, Boulton became more and more desirous of applying the engine to the various purposes of rotary motion. In one of his visits to Wales, in 1781, he had seen a powerful copper-rolling mill driven by water, and when told that its defect was that it was liable to be stopped in summer during drought, he immediately asked—“Why not use our engine? It goes night and day, summer and winter, and is altogether unaffected by drought.” Immediately on his return home, he made a model of a steam rolling-mill, with two cylinders and two beams, connecting the power by a horizontal axis; and by the end of the year he had a steam forge erected at Soho on this plan. “It answers very well,” he wrote to Matthews, “and astonishes all the ironmasters; for, although it is a small engine, it draws even more steel per day than a large rolling-mill in this neighbourhood draws by water.” Mr. Wilkinson was so much pleased with it that he ordered one to be made on a large scale for the Bradley ironworks; and another was shortly after ordered for Rotherham. But the number of iron mills was exceedingly limited, and Boulton did not anticipate any large extension of business in that quarter. If, however, he could once get the rotary engine introduced as the motive power for corn and flour mills, he perceived that the demand would be considerable. Writing to Watt on the subject, he said, “When Wheal Virgin is at work, and all the Cornish business is in good train, we must look out for orders, as all our treaties are seemingly at an end, having none now upon the tapis. There is no other Cornwall to be found, and the most likely line for increasing the consumption of our engines is the application of them to mills, which is certainly an extensive field.”
Watt, on his return to Birmingham from Cornwall, proceeded to embody his plan for securing rotary motion in a working engine, so that he might be enabled to exhibit the thing in actual work. He was stimulated to action by the report which reached his ears that a person in Birmingham had set agoing a self-moving steam rotator, in imitation of his, on which he exclaimed, “Surely the Devil of Rotations is afoot! I hope he will whirl them into Bedlam or Newgate.”[244] Boulton, who had by this time gone to Cornwall for the winter, wrote to him from Cosgarne, “It is certainly expensive; but nevertheless I think, as we have so much at stake, that we should proceed to execute such rotatives as you have specified.... You should get a good workman or two to execute your ideas with despatch, lest they perish. The value of their wages for a year might be 100l., but it would be the means of our keeping the start that we now have of all others. But above all, there is nothing of more importance than the perfect completion of the double expansive reciprocating engine as soon as may be.”[245] Watt replied that he was busily occupied in getting the rotative motion applied to one of the Soho engines. “These rotatives,” said he, “have taken up all my time and attention for months, so that I can scarcely say that I have done anything which can be called business. Our accounts lie miserably confused. We are going on in a very considerable weekly expense at Soho, and I can see nothing likely to be produced from it which will be an equivalent.” Speaking of the prospect of further improvements, he added, “It is very possible that, excepting what can be done in improving the mechanics of the engine, nothing much better than we have already done will be allowed by Nature, who has fixed a ne plus ultra in most things.”[246]
While thus hopelessly proceeding with the rotative engine, Watt was disquieted by the intelligence which reached him from Boulton, as to the untoward state of affairs in Cornwall. At some of the most important mines, in which Boulton and Watt held shares, the yield had considerably fallen off, and the price of the ores being still very low, they had in a great measure ceased to be remunerative. Hence appeals were made to Boulton on all sides for an abatement of the engine dues. Unwilling to concede this, the adventurers proceeded to threaten him with the Hornblowers, whose engine they declared their intention of adopting. As, however, Boulton and Watt’s engines were all going exceedingly well, and as the Hornblowers had not yet been able to get one of their boasted engines to work satisfactorily,[247] the adventurers hesitated for the present to take any overt steps in the matter.
Boulton had a long and disagreeable battle to fight with the adventurers on this point, which lasted for many months, during which the Hornblowers continued to stimulate them with the agreeable prospect of getting rid of the dues payable in respect of the savings of fuel by the condensing engines. Boulton resisted them at every point single-handed; the battle being, as he said, “Boulton and Watt against all Cornwall.”[248] He kept Watt fully informed from day to day of all that passed, and longed for more rapid means of communication,—the postal service being then so defective that no less than thirteen days elapsed before Boulton, at Truro, could receive an answer from Watt at Birmingham. On one occasion we find Watt’s letter eleven days on the road between the two places. The partners even had fears that their letters were tampered with in transit; and, in order to carry on their correspondence confidentially, Watt proposed to employ a shorthand alphabet, which he had learnt from Dr. Priestley, in which to write at least the names of persons, “as our correspondence,” he observed, “ought to be managed with all possible secrecy, especially as to names.”
Boulton, as usual, led a very active life in Cornwall. Much of his time was occupied in riding from mine to mine, inspecting the engines at work, and superintending the erection of others. The season being far advanced, the weather was bad, and the roads miry; but, wet or dry, he went his rounds. In one of his letters he gives an account of a miserable journey home on horseback, on a certain rainy, windy, dark night in November, when he was “caught in water up to 12 hands.” “It is very disagreeable,” he adds, “that one cannot stay out till dark upon the most emergent business without risking one’s life.” But once at home he was happy. “The greatest comfort I find here,” he says, “is in being shut out from the world, and the world from me. At the same time I have quite as much visiting as I wish for.” One of his favourite amusements was collecting and arranging fossils, some for his friend Wedgwood, and others for his own “fossilry” at Soho. Boulton was well supported out of doors by William Murdock, now regarded as “the right hand” of the concern in Cornwall.
“Murdock hath been indefatigable,” he wrote Watt, “ever since they began [at Wheal Virgin new Engine]. He has scarcely been in bed or taken necessary food.... After slaving day and night on Thursday and Friday, a letter came from Wheal Virgin that he must go instantly to set their engine to work or they would let out the fire. He went and set the engine to work: it worked well for the five or six hours he remained. He left it and returned to the Consolidated Mines about eleven at night, and was employed about the engines till four this morning, and then went to bed. I found him at ten this morning in Poldice Cistern, seeking for pins and casters that had jumped out, when I insisted on his going home to bed.”[249]
On one occasion, when an engine superintended by Murdock stopped through some accident occurring to it, the water rose in the mine, and the miners were drowned out. Upon this occurring, they came “roaring at him” for having thrown them out of work, and threatened to tear him to pieces. Nothing daunted, he went through the midst of the men, and proceeded to the invalided engine, which he succeeded in very shortly repairing and setting to work again. The miners were so rejoiced that they were carried by their feelings into the opposite extreme; and when he came out of the engine-house they cheered him vociferously, and insisted upon carrying him home on their shoulders in triumph!
About this time, Boulton became increasingly anxious to ascertain what the Hornblowers were doing. They continued to brag of the extraordinary powers of the engine erected by them at Radstoke, near Bristol, whither he proposed to go, to ascertain its construction and qualities, as well as to warn the persons who were employing them as to the consequences of their infringing the existing patent. But he was tied to Cornwall by urgent business, and could not leave his post for a day. “During the forking of these two great mines,” said he, “I dare not stir two miles from the spot, and it will yet be six weeks before I regain my liberty.”[250] He determined, therefore, to send over James Law, a Soho man on whom he could rely, to ascertain, if possible, the character of the new engine, and he also asked his partner Watt to wait upon the proprietors of Radstoke so soon as he could make it convenient to do so. Law accordingly proceeded to Radstoke, and soon found out where the engine was; but as the Horners were all in the neighbourhood, keeping watch and ward over it turn and turn about, he was unable to see it except through the engine-house window, when it was not working. He learnt, however, that there was something seriously wrong with it, and that the engineers were considerably crestfallen about its performances.
Watt proceeded to Bristol, as recommended by his partner, for the purpose of having a personal interview with Hornblower’s employers. On his arrival, he found that Major Tucker, the principal partner, was absent; and though he succeeded in seeing Mr. Hill, another of the partners, he could get no satisfactory reply from him as to the intentions of the firm with respect to the new engine. Having travelled a hundred miles on his special errand, Watt determined not to return to Birmingham until he had seen the principal partner. On inquiry he found that Major Tucker had gone to Bath, and thither Watt followed him. At Bath he found that the Major had gone to Melcompton. Watt took a chaise and followed him. The Major was out hunting; and Watt waited impatiently at a little alehouse in the village till three o’clock, when the Major returned—“a potato-faced, chuckle-headed fellow, with a scar on the pupil of one eye. In short,” said Watt, “I did not like his physiog.” After shortly informing the Major of the object of his visit, who promised to bring the subject under the notice of his partners at a meeting to be held in about three weeks’ time, Watt, finding that he could do no more, took his leave; but, before he left Bristol, he inserted in the local papers an advertisement, prepared by Boulton, cautioning the public against using the Hornblowers’ engine, as being a direct infringement of their patent. For the present, indeed, there seemed but little reason to apprehend danger from the Hornblowers, whose engine was still undergoing alterations in detail, if not in principle; and it appeared doubtful, from the trials which had been made of it, whether it would ever prove an economical working engine.
Watt then returned to Birmingham, to proceed with the completion of his rotary motion. Boulton kept urging that the field for pumping-engines was limited, that their Cornish prospects were still gloomy, and that they must very soon look out for new fields. One of his schemes was the applying of the steam-engine to the winding of coals. “A hundred engines at 100l. a year each,” he said, “would be a better thing than all Cornwall.” But the best field of all, he still held, was mills. “Let us remember,” said he, “the Birmingham motto, to ‘strike while the iron is hot.’”
Watt, as usual, was not so sanguine as his partner, and rather doubtful of the profit to be derived from this source. From a correspondence between him and Mr. William Wyatt, of London, on the subject, we find him discouraging the scheme of applying steam-engines to drive corn-mills; on which Boulton wrote to Wyatt,—
“You have had a correspondence with my friend Watt, but I know not the particulars.... You must make allowance in what Mr. Watt says ... he under values the merits of his own works.... I will take all risks in erecting an engine for a corn-mill.... I think I can safely say our engine will grind four times the quantity of corn per bushel of coal compared with any engine hitherto erected.”[251]
About the same time we find Boulton writing to Watt,—
“You seem to be fearful that mills will not answer, and that you cannot make Reynolds’s amount to more than 20l. a year. For my part, I think that mills, though trifles in comparison with Cornish engines, present a field that is boundless, and that will be more permanent than these transient mines, and more satisfactory than these inveterate, ungenerous, and envious miners and mine lords. As to the trouble of small engines, I would curtail it by making a pattern card of them (which may be done in the course of next year), and confine ourselves to those sorts and sizes until our convenience admits of more.”[252]
In the mean time Watt, notwithstanding his doubts, had been proceeding with the completion of his rotative machine, and by the end of the year applied it with success to a tilt-hammer, as well as to a corn-mill at Soho. Some difficulties presented themselves at first, but they were speedily surmounted. The number of strokes made by the hammer was increased from 18 per minute in the first experiment, to 25 in the second; and Watt contemplated increasing the speed to even 250 or 300 strokes a minute, by diminishing the height to which the hammer rose before making its descending blow. “There is now no doubt,” said he, “that fire-engines will drive mills; but I entertain some doubts whether anything is to be got by them, as by any computation I have yet made of the mill for Reynolds [recently ordered] I cannot make it come to more than 20l. per annum, which will do little more than pay trouble. Perhaps some others may do better.”[253]
“OLD BESS.”[254]
The problem of producing rotary motion by steam-power was thus solved to the satisfaction even of Watt himself. But though a boundless field for the employment of the engine now presented itself, Watt was anything but elated at the prospect. For some time he doubted whether it would be worth the while of the Soho firm to accept orders for engines of this sort. When Boulton went to Dublin to endeavour to secure a patent for Ireland, Watt wrote to him thus:—“Some people at Burton are making application to us for an engine to work a cotton-mill; but from their letter and the man they have sent here, I have no great opinion of their abilities.... If you come home by way of Manchester, please not to seek for orders for cotton-mill engines, because I hear that there are so many mills erecting on powerful streams in the north of England, that the trade must soon be overdone, and consequently our labour may be lost.” Boulton, however, had no such misgivings. He foresaw that before long the superior power, regularity, speed, and economy, of the steam-engine, must recommend it for adoption in all branches of manufacture in which rotative motion was employed; and he had no hesitation in applying for orders notwithstanding the opposition of his partner. The first rotary engine was made for Mr. Reynolds, of Ketley, towards the end of 1782, and was used to drive a corn-mill. It was some time before another order was received, though various inquiries were made about engines for the purpose of polishing glass, grinding malt, rolling iron, and such like.[255] The first engine of the kind erected in London was at Goodwyn and Co.’s brewery; and the second, still working, though in an altered form, at the Messrs. Whitbread’s. These were shortly followed by other engines of the same description, until there was scarcely a brewery in London that was not supplied with one.
In the mean time, the works at Soho continued to be fully employed in the manufacture of pumping-engines. But as the county of Cornwall was becoming well supplied,—no fewer than twenty-one having now been erected there, only one of the old Newcomen construction continuing in work,—it was probable that before long the demand from that quarter must slacken, if not come to an end. There were, however, other uses to which the pumping-engine might be applied; and one of the most promising was the drainage of the Fen lands. Some adventurers at Soham, near Cambridge, having made inquiries on the subject, Watt wrote to his partner, “I look upon these Fens as the only trump card we have left in our hand.”[256] The adventurers proposed that Boulton and Watt should take an interest in their scheme by subscribing part of the necessary capital. But Watt decidedly objected to this, as he did not wish to repeat his Cornish difficulties in the Fens. He was willing to supply engines on reasonable terms, but as for shares he would have none of them. The conclusion he eventually arrived at with respect to his proposed customers was this,—“Consider Fen men as Cornish men, only more cunning.”
In the midst of his great labours, Boulton was reminded that he was human. He had for years been working at too high pressure, and the tear and wear began to tell upon his health. Watt expostulated with him, telling him that he was trying to do half-a-dozen men’s work; but in vain. He was committed to so many important enterprises—he had so much at stake—the liabilities he had to meet from day to day were so heavy—that he was in a measure forced to be active. To his friend Matthews he lamented that he was under the necessity of “slaving from morning till night, working fourteen hours a day, in the drudgery of a Birmingham manufacturer and hardware merchant.” But this could not last, and before long he was threatened with a break-down. His friends Drs. Withering and Darwin urged him at once to “knock off” and take a long holiday—to leave Soho and its business, its correspondence, and its visitors, and get as far away from it as possible.
Acting on their advice, he resolved on making a long-promised visit to Scotland, and he set out on his tour in the autumn of 1783. He went by Newcastle, where he visited the principal coal mines, and from thence to Edinburgh, where he had some pleasant intercourse with Dr. Black and Professor Robison. It is evident from his letters that he did not take much ease during his journey, for he carried about with him his steam-engine—at least in his head. “I talked with Dr. Black and another chemical friend,” he wrote, “respecting my plan for saving alkali at such bleach-grounds as our fire-engines are used at instead of water-wheels: the Doctor did not start any objections, but, on the contrary, much approved it.” From Edinburgh he proceeded to the celebrated ironworks at Carron, a place in which he naturally felt a peculiar interest. There his friend Roebuck had started his great enterprise, and there Watt had erected his first engine. His visit there, however, was not so much for curiosity or pleasure, but for business and experiment. “During my residence in Scotland,” said he, “one month of my time was closely employed at Carron Ironworks in settling accounts, but principally in making a great number of experiments on all their iron ores, and in putting them into the train of making good bar-iron, in which I succeeded to my wishes, although they had never made a single bar of tough iron at Carron before.”[257] In the course of his journey he made a large collection of fossils for his museum, and the weight of his bags sensibly increased almost daily. On his way through Ayrshire he called on Lord Dundonald, a kindred spirit in chemical and mechanical scheming, and examined his mineral tar works. He wrote to Mr. Gilbert, the Duke of Bridgewater’s manager at Worsley, that “the tar is better for the bottoms of vessels than the vegetable tar; and the coal-oil hath many uses. Query—if such a work might not be a useful appendage to your colliery and canal.”
Boulton returned to Soho greatly improved in health, and was shortly immersed as before in the business of the factory. He found considerable arrears of correspondence requiring to be brought up. Several of the letters waiting for him were from schemers of new inventions connected with the steam-engine. Whenever an inventor thought he had discovered anything new, he at once rushed to Boulton with it. He was looked upon as the lord and leader of steam power. His reputation for enterprise and business aptitude, and the energetic manner in which he had pushed Watt’s invention, were now so widely known, that every new schemer saw a fortune within his reach could he but enlist Boulton on his side. Hence much of his time was occupied in replying to letters from schemers,—from inventors of perpetual motion, of flying-machines, of locomotion by steam, and of various kinds of rotary motion. In one of his letters we find him complaining of so much of his time being “taken up in answering great numbers of letters he had lately been plagued with from eccentric persons of no business;” for it was his practice never to leave a letter unanswered, no matter how insignificant or unreasonable his correspondent might be.[258]
After a short visit to London, Boulton proceeded into Cornwall to look after the engines there, and watch the progress of the mining operations in which by this time he had become so largely interested. He found the adventurers in a state of general grumble at the badness of the times, the lowness of prices, the losses incurred in sinking for ore that could not be found, and the heaviness of the dues for engine-power payable to Boulton and Watt. At such times, the partners were usually beset with applications for abatement, to which they were under the necessity of submitting to prevent the mines being altogether closed. Thus the dues at Chacewater were reduced from 2500l. to 1000l. a year, and the adventurers were still pressing for further reductions.[259] What provoked Boulton most, however, was, not the loss of dues so much as the threats which were constantly held out to him that unless the demands of the adventurers were complied with, they would employ the Hornblowers.
“It is a disagreeable thing,” he wrote, “to live amongst one’s enemies, and all the adventurers are so, except Phillips and the Foxes, who are fair men although they would rather have engines free. I have had many hints given me that the Trumpeters were reviving their mischief, and many causes for uneasiness, but I did not wish you to partake of them, and therefore have been silent; but they are now striking at the root of us, and therefore we must defend ourselves or fall.... I think if we could but keep up our spirits and be active we might vanquish all the host. But I must own that I have been low-spirited ever since I have been here—have been indolent, and feel as if the springs of life were let down.”
It does not, however, appear from the letter to Watt in which this complaint occurs, that Boulton had been at all indolent, as he speaks of being in almost daily attendance at the miners’ meetings; one day at Poldice, the next at Consolidated Mines, and so on. Of the latter meeting he says,—
“There was a full attendance; Jethro looked impudent, but mortified to see the new little engine drawing kibbles from two pits exceedingly well and very manageable, and afterwards it worked six stamps each 2½ = 14 cwt., lifted twice at each revolution, or four times for every stroke of the engine. I suppose there were a thousand people present to see the engine work.”
Watt was, on his part, rather opposed to making further concessions, which only seemed to have the effect of inviting demands for more.
“People,” said he, “do not employ us out of personal regard, but to serve themselves; and why should not we look after ourselves in like manner.... John Taylor died the other day worth 200,000l., without ever doing one generous action. I do not mean that we should follow his example. I should not consent to oppression or to take any unfair advantage of my neighbour’s necessity, but I think it blameable to exercise generosity towards men who display none towards us. It is playing an unfair game when the advantage is wholly on their side. If Wheal Virgin threatened to stop unless we abated one-half, they should stop for me; but if it appeared that, according to the mode settled in making the agreement, we had too high a premium, I should voluntarily reduce it to whatever was just.”
While Boulton was fighting for dues in Cornwall, and labouring as before to improve the business management of the mines in which he was interested as a shareholder, Watt was busily occupied at Soho in turning out new engines for various purposes, as well as in perfecting several long-contemplated inventions. The manufactory, which had for a time been unusually slack, was again in full work. Several engines were in hand for the London brewers. Wedgwood had ordered an engine to grind flints;[260] and orders were coming in for rotative engines for various purposes, such as driving saw-mills in America and sugar-mills in the West Indies. Work was, indeed, so plentiful that Watt was opposed to further orders for rotatives being taken, as the drawings for them occupied so much time, and they brought in but small profit. “I see plainly,” said he, “that every rotation engine will cost twice the trouble of one for raising water, and will in general pay only half the money. Therefore I beg you will not undertake any more rotatives until our hands are clear, which will not be before 1785. We have already more work in hand than we have people to execute it in the interval.”[261]
One reason why Watt was more than usually economical of his time was, that he was then in the throes of the inventions patented by him in the course of this year. Though racked by headaches which, he complained, completely “dumfounded” him and perplexed his mind, he could not restrain his irrepressible instinct to invent; and the result was the series of inventions embodied in his patent of 1784, including, among other things, the application of the steam-engine to the working of a tilt-hammer for forging iron and steel, to driving wheel-carriages for carrying persons and goods, and for other purposes. The specification also included the beautiful invention of the parallel motion, of which Watt himself said, “Though I am not over anxious after fame, yet I am more proud of the parallel motion than of any other mechanical invention I have ever made.” Watt was led to meditate this contrivance by the practical inconvenience which he experienced in communicating the direct vertical motion of the piston-rod by means of racks and sectors, to the angular motion of the working beam. He was gradually led to entertain the opinion that some means might be contrived for accomplishing this object by motions turning upon centres; and, working upon this idea, he gradually elaborated his invention. So soon as he caught sight of the possible means of overcoming the difficulty, he wrote to Boulton in Cornwall,—
“I have started a new hare. I have got a glimpse of a method of causing a piston-rod to move up and down perpendicularly by only fixing it to a piece of iron upon the beam, without chains or perpendicular guides or untowardly friction, arch heads, or other pieces of clumsiness; by which contrivance it answers fully to expectation. About 5 feet in the height of her house may be saved in 8-feet strokes, which I look upon as a capital saving, and it will answer for double engines as well as for single ones. I have only tried it in a slight model yet, so cannot build upon it, though I think it a very probable thing to succeed. It is one of the most ingenious, simple pieces of mechanism I have ever contrived, but I beg nothing may be said on it till I specify.”[262]
THE PARALLEL MOTION.
He immediately set to work to put his idea to the practical proof, and only eleven days later he wrote,—
“I have made a very large model of the new substitute for racks and sectors, which seems to bid fair to answer. The rod goes up and down quite in a perpendicular line without racks, chains, or guides. It is a perpendicular motion derived from a combination of motions about centres—very simple, has very little friction, has nothing standing higher than the back of the beam, and requires the centre of the beam to be only half the stroke of the engine higher than the top of the piston-rod when at lowest, and has no inclination to pull the piston-rod either one way or another, only straight up and down.... However, don’t pride yourself on it—it is not fairly tried yet, and may have unknown faults.”[263]
THE GOVERNOR.
Another of Watt’s beautiful inventions of the same period, was the Governor, contrived for the purpose of regulating the speed of the engine. This was a point of great importance in all cases where steam-power was employed in processes of manufacture. To modify the speed of the piston in the single-acting pumping-engine, Watt had been accustomed to use what is called a throttle valve, which was regulated by hand as occasion required. But he saw that to ensure perfect uniformity of speed, the action of the engine must be made automatic if possible, and with this object he contrived the Governor, which has received no improvement since it left his hand. Two balls are fixed to the ends of arms connected with the engine by a moveable socket, which plays up and down a vertical rod revolving by a band placed upon the axis or spindle of the fly-wheel. According to the centrifugal force with which the balls revolve, they diverge more or less from the central fixed point, and push up or draw down the moveable collar; which, being connected by a crank with the throttle-valve, thereby regulates with the most perfect precision the passage of the steam between the boiler and the cylinder. When the pressure of steam is great, and the tendency of the engine is to go faster, the governor shuts off the steam; and when it is less, the governor opens the throttle-valve and increases the supply. By this simple and elegant contrivance the engine is made to regulate its own speed with the most beautiful precision.
Among the numerous proposed applications of the steam-engine about this time, was its employment as a locomotive in driving wheel-carriages. It will be remembered that Watt’s friend Robison had, at a very early period, directed his attention to the subject; and the idea had since been revived by Mr. Edgeworth, who laboured with great zeal to indoctrinate Watt with his views. The latter, though he had but little faith in the project, nevertheless included a plan of a locomotive engine in his patent of 1784; but he took no steps to put it in execution, being too much engrossed with other business at the time. His plan contemplated the employment of steam either in the form of high-pressure or low-pressure, working the pistons by the force of steam only, and discharging it into the atmosphere after it had performed its office, or discharging it into an air-tight condenser made of thin plates or pipes, with their outsides exposed to the wind or to an artificial current of air, thereby economising the water which would otherwise be lost.
Watt did not carry his design into effect; and, so far as he was concerned, the question of steam locomotion would have gone no further. But the subject had already attracted the attention of William Murdock, who had for some time been occupied during his leisure hours in constructing an actual working model of a locomotive. When his model was finished, he proceeded to try it in the long avenue leading to the parsonage at Redruth, in the summer of 1784; and in so doing nearly frightened out of his wits the village pastor, who encountered the hissing, fiery little machine, while enjoying his evening walk.[264]
When Watt heard of this experiment, he wrote to Boulton, advising that Murdock should be gently counselled to give up his scheme, which might have the effect of withdrawing him from the work of the firm, in which he had become increasingly useful.
“As to my own part,” wrote Watt, “I shall form no obstacle to the scheme. My only reasons against it were that I feared it would deprive us of a valuable man; that it would, if we were to be concerned in it, divert us from more valuable business, and perhaps prove a sinking fund; and lastly, that I did not like that a scheme which I had revolved in my mind for years and hoped to be able at some favourable time to bring to perfection, if capable of it, should be wrested from me, or that I should be compelled to go into it as a secondary person. But I have now made the latter objection give way. And as to the first, I think it will take place at any rate, so we must make the best of it.”[265]
Boulton was accordingly recommended in the first place to endeavour to dissuade Murdock from pursuing the subject further, but if he could not succeed in that, rather than lose him, he was to let him have an advance to the extent of 100l., to enable him to prosecute his experiments; and if within a year he succeeded in making an engine capable of drawing a postchaise carrying two ordinary persons and the driver, with 200 lbs. of luggage, fuel for four hours, and water for two hours, going at the rate of four miles an hour, then a partnership was to be entered into, in which Boulton and Watt were to find the capital, and Murdock was to conduct the business and take his share of the profits.
Murdock, however, had so many urgent matters to attend to, that, sanguine though he continued to be as to the success of his scheme, he could not find time to pursue it. He was a man after Boulton’s own heart, unsparing of himself and indefatigable in whatsoever he undertook; nor was Boulton sparing of praises of him in his confidential letters to Watt.