In 1776, after his settlement with his two boys in Birmingham, Watt found his way back to Scotland. Here he was fortunate in securing orders for the fire engine, and still more fortunate in securing as his second wife Miss Anne M’Gregor of Glasgow. He could ill be spared at Soho, and Boulton writes, ”If we had a hundred wheel engines ready made, and a hundred small engines, we could readily dispose of them. Therefore let us make hay while the sun shines, and fill our barns before the dark cloud of age lowers upon us, and before any more Tubal-Cains arise like the serpents of Moses to devour all others. As to your absence, say nothing about it; I will forgive it this time, provided you promise me never to marry again.”

The engines were principally demanded for the mining districts of Cornwall, where their efficiency in pumping the water out of the deep mines was at once manifest. At first, they charged a royalty for the use of their patent ÿviz., one third of the value of the saving of coal effected by their engine as compared to Newcomen’s. The uplifting of this royalty, the erecting of new engines, and the repair of those in use required a member of the firm to be always in the district. Watt undertook these duties. He had to contend not only with natural obstacles in the dark abysses of deeply flooded mines, but with a rude and obstinate class of men as deeply flooded by inveterate prejudices. His letters about this time remind us of the strains in which Ovid bewailed his exile to the remote and savage Pontus. “Peace of mind and delivery from Cornwall is my prayer. Those wilds might be defined a tract of hills without dales, where the roads go straight up the hills without flinching, and where the enginemen actually eat the grease from the engine.” And yet he must have been doing an enormous service to the mining interest, for he writes, “If we had not furnished them with more effectual means of drawing the water, I believe all the deep mines must have been abandoned.”

Many of his worries arose from the fact that he had to do so much personally. There were not workmen sufficiently skilled to be relied on. One exception he fortunately found whose name should not be forgotten in any account of Watt. This was William Murdoch, a relative of the John Murdoch who taught Robert Burns. Murdoch had assisted his father, farmer and miller, at Auchinleck. He had gained a fair knowledge of machinery, some practical experience at the bench, and had even designed and built bridges. Intelligent and ambitious, he had heard of Watt and his famous fire engine, and he resolved in 1777 to go to Birmingham and try whether he could get a job from the great engineer at Soho. He was then in his twenty-third year.