[ [254] The above illustration represents the first engine employed at Soho, with the alterations subsequently introduced, for the purpose of producing rotary motion. The old Kinneil engine, “Beelzebub,” as Watt called her, was entirely removed, and replaced by this engine, as explained by Watt in his MS. Memoir of Boulton now before us, wherein he states,—“The first engine of 18 inches cylinder, which was employed in returning the water to Soho mill, was replaced about 1778 or 1779 by a larger engine, the first on the expansive principle, which still remains there.” The engine became known at Soho as “Old Bess,” and she continued in regular work until within the last eight years. The illustration shows the state in which the engine now stands in South Kensington Museum.
A. steam cylinder; B. steam pipe; C. throttle valve; D. steam valve; E. eduction valve; F. eduction pipe; G. valve gearing; H. condenser; I. air pump; K. air pump rod; L. foot valve; M. hand gear tappet rod; N. parallel motion; O. balance weight; P. rocking beam; Q. connecting rod; R. feed pump rod; S. sun wheel; T. planet wheel; U. fly wheel; W. governor; X. feedwater cistern.
[ [255] “We have had a visit to-day from a Mr. Cort of Gosport, who says he has a forge there, and has found out some grand secret in the making of iron, by which he can make double the quantity at the same expense and in the same time as usual. He says he wants some kind of engine, but could not tell what; wants some of us to call on him, and says he had some correspondence with you on the subject. He seems a simple goodnatured man, but not very knowing. He says he has most of the smith-work for the king’s yard, and has a forge, a rolling and slitting mill. I think him a brother projector.”—Watt to Boulton, 14th December, 1782.
[ [256] 4th December, 1782.
[ [257] Letter to Thomas Knox, M.P.
[ [258] With an almost excess of politeness, Boulton wrote long letters to unknown correspondents to set them right about mechanical errors into which they seemed to him to have fallen. Thus a Mr. Knipe of Chelsea, supposing he had discovered a perpetual motion machine, wrote inviting Boulton to join him as a partner. Though the man was without means and evidently foolish, Boulton wrote him several long letters in the kindest spirit, pointing out that his scheme was contrary to reason and science. “It is impossible,” said he, “for inanimate mechanism to produce the least degree of power or to augment the sum total of the primum mobile. Mechanism may communicate or concentrate or economise power, but cannot create or augment it.” Knipe replied at great length, vindicating his invention. His enthusiasm pleased Boulton, who, in the generosity of his nature, sent him a draft for ten guineas on his London bankers to enable the poor inventor to secure his invention if there was really anything in it. But nothing more was heard of Knipe’s Perpetual Motion Machine.
[ [259] No wonder the miners were so urgent for reductions in working expenses, as we find from a communication from Watt to Boulton, of facts to be laid before Parliament against the proposed tax on coal, that Chacewater had sunk 50,000l. in setting the mine to work; Wheal Virgin 28,000l. in ten months, and still unprosperous; Poldice a very large sum, and merely paying expenses; Wheal Chance 35,000l., and only moderately prosperous; Pool 14,000l., without much prospect of recovery; Roskere languishing, and not paying expenses; United Mines, which had been at death’s door, still in a tottering state; Wheal Union stopped, after losing about 8000l.; Dalcoath 500l. spent on timber per month, and a new kibble-rope, of above a ton weight, worn out in a fortnight. [To draw a kibble of ore then, weighing about 3 cwt., took fully fifteen minutes, owing to the great depth of that mine, and two-thirds of the stuff drawn was stones.] To which Watt added, “if we had not furnished the miners with more effectual means of draining the water, almost all the deep mines would have been abandoned before now.”
[ [260] The engine was of 40-horse power. It was erected at the “Black Works,” Etruria, where it continues working with the sun and planet motion,—one of the very few engines of the old construction still remaining in existence.
[ [261] Watt to Boulton, 22nd June, 1784.
[ [262] Watt to Boulton, 30th June, 1784. Boulton MSS.