CHAPTER XII. WATT'S SINGLE-ACTING ENGINE FOR PUMPING WATER. NONE of Roebuck's creditors regarded Watt's engine as worth a farthing. Among his debts was a sum of 6301. due to Boulton. An arrangement was therefore made whereby Boulton took up Roebuck's share in the engine patent, by releasing him from the above debt, and by engaging to pay a further sum of 1,000l. out of the first profits derived from the engine. A mutual discharge was executed between Roebuck and Watt in May, 1773;1 and in the summer of the same year, the materials of the engine which had been built at Kinneil, were packed up and sent to Soho. About a year later, after completing his engagements in Scotland, Watt himself repaired to Soho and took up his residence there. Experiments with the engine were resumed forthwith, and were attended with more decided success. 1 Muirhead's Life of Watt, 2nd ed., pp. 237-8 CH. XII.] BOULTON-EXTENSION OF PATENT. 151 Writing to his father in December, 1774, Watt informs him that the fire engine he had invented was now going, and answered much better than any other that had yet been made; he expected the invention would prove very beneficial to him.1 Encouraged by the favourable results which had been obtained, early in 1775, Boulton applied for a better cylinder, to Mr. John Wilkinson, an eminent iron-founder, who had introduced a new boringmachine which was an immense improvement on the old one.2 The prospects of the engine now began to brighten, but already six years of the period named in the patent had expired. So far the invention had been only a source of expense. A further outlay of capital was required before the manufacture of engines for the public could be commenced. It became evident that the unexpired term of the patent right was too contracted to afford a reasonable prospect of any adequate remuneration being obtained. Under these circumstances it was decided to apply to Parliament for a prolongation of the term, and in May, 1775, Watt had the pleasure of informing his father that an Act of 1 Muirhead's Life of Watt, 2nd ed., p. 239. Mechanical Inventions of James Watt, Vol. II., p. 79. 2 On the 27th of January, 1774, a patent was granted to John Wilkinson of Broseley, in the county of Salop, ironmaster, for casting and boring guns, cannon, &c. Vide No. 1063. Parliament had been obtained, securing the monopoly of his invention for a term of twenty-five years.1 No time was now lost by Boulton and Watt in preparing for the manufacture of engines, and early in the following year two had been completed and set to work. "We have now two large engines going," says Watt in a letter to Smeaton, dated April, 1776, "one about ten miles from Birmingham, the cylinder fifty inches diameter, intended to work a fourteen-and-a-quarter inch working barrel, to lift water from 100 yards deep; but the pit is only sunk to forty yards at present, they have a good deal of water, and the engine goes constantly. Their boiler is twelve-and-a-half feet diameter and is very bad, and the cylinder is not protected from the cold air. They burn only twenty-five hundredweight of the sweepings of an old coal-hill in twelve hours. I have never seen this engine go, so can tell you nothing more about it. "The other engine is a thirty-eight inch cylinder, which blows an iron furnace at New Willey, in Shropshire; it acts immediately to compress the air in a blowing cylinder seventy-two inches diameter and seven feet stroke; as that cylinder is very rough and unevenly bored, I am uncertain what power it exerts, but it raises a column of water five-and-a-half feet high, in the air-chest of the water regulator, and goes fourteen strokes per minute, that is, a column of water seventy-two inches diameter, and five-and-a-half feet high. When I left it, there were several things unfinished; yet the quantity of fuel used seemed to be very moderate. Both these engines please even the workmen, who are all sufficiently captious. We are going on with several other large engines; one of a fifty-eight inch cylinder in Warwickshire, and our concern wears a business-like face. 1 Muirhead's Life of Watt, 2nd ed., p. 242; Mechanical Inventions of James Watt, Vol. II., p. 89. XII.] WATT'S ENGINE A SUCCESS. 153 "Mr. Wilkinson has improved the art of boring cylinders; so that I promise upon a seventy-two inch cylinder being not further distant from absolute truth than the thickness of a thin sixpence in the worst part. I am labouring to improve the regulators; my scheme is to make them acute conical valves, shut by a weight, and opened by the force of the steam. They bid fair of success, and will be tried in a few days.” 1 1 The superiority of Watt's engine over Newcomen's, in power and economy of fuel, was soon demonstrated, and the success of the invention assured. People came daily to Soho to see the engines; the Cornish miners, who perhaps more than any others were interested in an economical engine, renewed their inquiries about it.2 Orders from many quarters flowed in apace. "I have an application for an engine from a distiller at Bristol," says Boulton in a letter to Watt, dated 25th July, 1776, "to raise 15,000 ale gallons per hour 60 feet high; I have another for a coal-mine in Wales, another for a Mr. Langdale in Holborn, a distiller, and another for Mr. Liptrap, at Mile End, a distiller." Towards the end of the same year, orders for engines began to arrive from Cornwall, and this county soon became the principal sphere for the application of the improved 1 Farey on the Steam Engine, p. 320, note. 2 Mechanical Inventions of James Watt, Vol. II., p. 98. As early as April, 1775, the Cornish mine-owners were becoming impatient to know the issue of Boulton and Watt's application to Parliament, and the terms they would propose in the event of an Act being obtained. [Ibid. p. 85.] 3 Mechanical Inventions of James Watt, Vol. II., p. 101. engines. So rapid was the adoption of Watt's engine in Cornwall, that in the short space of five or six years from their first introduction, all the engines in the county had been altered, with only one exception.1 In April, 1777, Smeaton went to see one of Watt's engines which had been erected at a distillery at Stratford-le-Bow, near London. He said "it was a pretty engine, but it appeared to him to be too complex."2 Though Smeaton's own improvements on the fire engine were so signally eclipsed by the invention of Watt, much to his honour he acted towards Watt and his partner with the utmost candour and friendship, and even recommended a customer to them more than once.3 The royalty charged by Boulton and Watt for the 1 Muirhead's Life of Watt, 2nd ed., p. 265. In the colliery districts the atmospheric engines were much more slowly superseded—a few have even survived to the present day. At Whitehaven Collieries, in Cumberland, an atmospheric engine having a seventy inch cylinder is still employed in pumping. It was built in 1805, and is provided with a separate condenser. It works with a pressure of steam of 5 lbs. on the square inch above the atmosphere. The writer is informed on reliable authority that several others are still in use at collieries in the Midland Counties. 2 Mechanical Inventions of James Watt, Vol. II., p. 103. Smeaton was of opinion that Watt's engine would never be generally introduced on account of the difficulty of getting the parts of it made with the requisite precision. See Muirhead's Life of Watt, 2nd ed. pp. 24950. Smiles's Lives of the Engineers, "Boulton and Watt," ed. 1874, p. 163. 3 Ibid., |