By this time Roebuck was becoming embarrassed with debt, and involved in various difficulties. The pits were drowned with water, which no existing machinery could pump out, and ruin threatened to overtake him before Watt’s engine could come to his help. He had sunk in the coal-mine, not only his own fortune, but much of the property of his relatives; and he was so straitened for money that he was unable to defray the cost of taking out the engine patent according to the terms of his engagement, and Watt had accordingly to borrow the necessary money from his never-failing friend, Dr. Black. He was thus adding to his own debts, without any clearer prospect before him of ultimate relief. No wonder that he should, after his apparently fruitless labour, express to Small his belief that, “of all things in life, there is nothing more foolish than inventing.” The unhappy state of his mind may be further inferred from his lamentation expressed to the same friend on the 31st of January, 1770. “To-day,” said he, “I enter the thirty-fifth year of my life, and I think I have hardly yet done thirty-five pence worth of good in the world; but I cannot help it.”
Notwithstanding the failure of his engine thus far, and the repeated resolution expressed to Small that he would invent no more, leading, as inventing did, to only vexation, failure, loss, and increase of headache, Watt could not control his irrepressible instinct to invent; and whether the result might be profitable or not, his mind went on as before, working, scheming, and speculating. Thus, at different times in the course of his correspondence with Small, who was a man of a like ingenious turn of mind, we find him communicating various new things, “gimcracks,” as he termed them, which he had contrived. He was equally ready to contrive a cure for smoky chimneys, a canal sluice for economising water, a method of determining “the force necessary to dredge up a cubic foot of mud under any given depth of water,” and a means of “clearing the observed distance of the moon from any given star of the effects of refraction and parallax;” illustrating his views by rapid but graphic designs embodied in the text of his letters to Small and other correspondents. One of his minor inventions was a new method of readily measuring distances by means of a telescope.[88] At the same time he was occupied in making experiments on kaolin, with the intention of introducing the manufacture of porcelain in the pottery work on the Broomielaw, in which he was a partner. He was also concerned with Dr. Black and Dr. Roebuck in pursuing experiments with the view of decomposing sea-salt by lime, and thereby obtaining alkali for purposes of commerce. A patent for the process was taken out by Dr. Roebuck, but eventually proved a failure, like most of his other projects. We also find Watt inventing a muffling furnace for melting metals, and sending the drawings to Mr. Boulton at Birmingham for trial. At other times he was occupied with Chaillet, the Swiss dyer, experimenting on various chemical substances; corresponding with Dr. Black as to the new fluoric or spar acid; and at another time making experiments to ascertain the heats at which water boils at every inch of mercury from vacuo to air. Later we find him inventing a prismatic micrometer for measuring distances, which he described in considerable detail in his letters to Small.[89] He was at the same time busy inventing and constructing a new surveying quadrant by reflection, and making improvements in barometers and hygrometers. “I should like to know,” he wrote to Small, “the principles of your barometer: De Luc’s hygrometer is nonsense. Probavi.” Another of his contrivances was his dividing-screw, for dividing an inch accurately into 1000 equal parts. He states that he found this screw exceedingly useful, as it saved him much needless compass-work, and, moreover, enabled him to divide lines into the ordinates of any curve whatsoever.
Such were the multifarious pursuits in which this indefatigable student and inquirer was engaged; all tending to cultivate his mind and advance his education, but comparatively unproductive, so far as regarded pecuniary return. So unfortunate, indeed, had Watt’s speculations proved, that his friend Dr. Hutton, of Edinburgh, addressed to him a New-year’s day letter, with the object of dissuading him from proceeding further with his unprofitable brain-distressing work. “A happy new year to you!” said Hutton; “may it be fertile to you in lucky events, but no new inventions!” He went on to say that invention was only for those who live by the public, and those who from pride choose to leave a legacy to the public. It was not a thing likely to be well paid for under a system where the rule was to be the best paid for the work that was easiest done. It was of no use, however, telling Watt that he must not invent. One might as well have told Burns that he was not to sing because it would not pay, or Wilkie that he was not to paint, or Hutton himself that he was not to think and speculate as to the hidden operations of nature. To invent was the natural and habitual operation of Watt’s intellect, and he could not restrain it.
Watt had already been too long occupied with this profitless work: his money was all gone; he was in debt; and it behoved him to turn to some other employment by which he might provide for the indispensable wants of his family. Having now given up the instrument-making business, he confined himself almost entirely to surveying. Among his earliest surveys was one of a coal canal from Monkland to Glasgow, in 1769; and the Act authorising its construction was obtained in the following year. Watt was invited to superintend the execution of the works, and he had accordingly to elect whether he would go on with the engine experiments, the event of which was doubtful, or embrace an honourable and perhaps profitable employment, attended with much less risk and uncertainty. His necessities decided him. “I had,” he said, “a wife and children, and saw myself growing grey without having any settled way of providing for them.” He accordingly accepted the appointment offered him by the directors of the canal, and undertook to superintend the construction of the works at a salary of 200l. a year. At the same time he determined not to drop the engine, but to proceed with it at such leisure moments as he could command.
The Monkland Canal was a small concern, and Watt had to undertake a variety of duties. He acted at the same time as surveyor, superintendent, engineer, and treasurer, assisted only by a clerk. But the appointment proved useful to him. The salary he earned placed his family above want, and the out-doors life he was required to lead improved his health and spirits. After a few months he wrote Dr. Small that he found himself more strong, more resolute, less lazy, and less confused, than when he began the occupation. His pecuniary affairs were also more promising. “Supposing the engine to stand good for itself,” he said, “I am able to pay all my debts and some little thing more, so that I hope in time to be on a par with the world.” But there was a dark side to the picture. His occupation exposed him to fatigue, vexation, hunger, wet, and cold. Then, the quiet and secluded habits of his early life did not fit him for the out-door work of the engineer. He was timid and reserved, and had nothing of the navvy in his nature. He had neither the roughness of tongue nor stiffness of back to enable him to deal with rude labour gangs. He was nervously fearful lest his want of practical experience should betray him into scrapes, and lead to impositions on the part of his workmen. He hated higgling, and declared that he would rather “face a loaded cannon than settle an account or make a bargain.” He had been “cheated,” he said, “by undertakers, and was unlucky enough to know it.”
Watt continued to act as engineer for the Monkland Canal Company for about a year and a half,[90] during which he was employed in other engineering works. Among these was a survey of the river Clyde, with a view to the improvement of the navigation. Watt sent in his report; but no steps were taken to carry out his suggestions until several years later, when the beginning was made of a series of improvements, which have resulted in the conversion of the Clyde from a pleasant trouting and salmon stream into one of the busiest navigable highways in the world.[91]
Among Watt’s other labours about the same period may be mentioned his survey of a canal between Perth and Cupar Angus, through Strathmore; of the Crinan Canal, afterwards carried out by Rennie; and other projects in the western highlands. The Strathmore Canal survey was conducted at the instance of the Commissioners of Forfeited Estates. It was forty miles long, through a very rough country. Watt set out to make it in September, 1770, and was accompanied by snowstorms through almost the entire survey. He suffered severely from the cold: the winds swept down from the Grampians with fury and chilled him to the bone. The making of this survey occupied him forty-three days, and the remuneration he received for it was only eighty pounds, which included expenses. The small pay of engineers at that time may be further illustrated by the fee paid him in the same year for supplying the magistrates of Hamilton with a design for the proposed new bridge over the Clyde at that town. It was originally intended to employ Mr. Smeaton; but as his charge was ten pounds, which was thought too high, Watt was employed in his stead. The Burgh minutes record that, after the Act had been obtained in 1770, Baillie Naismith was appointed to proceed to Glasgow to see Mr. Watt on the subject of a design, and his charge being only 7l. 7s., he was requested to supply it accordingly. “I have lately,” wrote Watt to Small, “made a plan and estimate of a bridge over our river Clyde, eight miles above this: it is to be of five arches and 220 feet waterway, founded upon piles on a muddy bottom.”[92] The bridge, after Watt’s plan, was begun in 1771, but it was not finished until 1780.[93]
HAMILTON BRIDGE.
About the same time Watt prepared plans of docks and piers at Port Glasgow, and of a new harbour at Ayr. The Port Glasgow works were carried out, but those at Ayr were postponed. When Rennie came to examine the design for the improvement of the Ayr navigation, of which the new harbour formed part, he took objections to it, principally because of the parallelism of the piers, and another plan was eventually adopted. His principal engineering job, and the last of the kind on which Watt was engaged in Scotland, was a survey of the Caledonian Canal, long afterwards carried out by Telford. The survey was made in the autumn of 1773, through a country without roads. “An incessant rain,” said he, “kept me for three days as wet as water could make me; I could hardly preserve my journal book.”