[ [372] From a memorandum found amongst Mr. Boulton’s papers, we learn that the following were the details of Symington’s engine:—“Engine hath two cylinders of 18 inches diameter each and 2 feet stroke. The rods of each piston are connected to a circular barrel of cast iron by means of chains, so that whilst one piston moves down the other ascends, and so gives the barrel a reciprocating motion. Upon the axis of the barrel is an arm or lever which works the plug and working gear. Each of the cylinders hath 2 pistons, one at top and the other at bottom; the 2 bottom pistons have their rods moving in stuffing-boxes and are connected together by a beam. The steam is admitted into the cylinder at its side, between the 2 pistons, and moves the one up and the other down; but the motion of the upper is greater than the under. When the upper piston is got to the top and the under one to the bottom, the steam valve is shut and the exhaustion one opened; by which the steam is admitted into the bottom of the cylinder, and is in its way met by a jet of cold water, which condenses it, and then it is squeezed out by the under piston, which in fact makes the bottom of the cylinder an air-pump. Whilst this condensation is going forward in the one cylinder, the steam is operating in the other, and vice versâ.”
[ [373] “I am now satisfied,” he said, “that Mr. Symington’s steam-engine is the most improper of all steam-engines for giving motion to a vessel, and that he does not know how to calculate frictions or mechanical powers. By means of a new well-constructed valve-wheel, and the pinion being doubled in diameter, I doubt not that the velocity of the vessel’s motion will be increased; but, do as you will, a great deal of power of the engine must be lost in friction. I remember well that when the small engine was wrought in the boat at Dalswinton, I had formed the same idea, and that I told you so; but not having studied the subject, I gave up my own common sense. This is now past remedy. As the engine cannot be of use to me now, I hope, with the aid of Mr. Tibbets and Mr. Stainton, you will get it sold before you leave Carron.”—Miller to Taylor, 7th December, 1789.
[ [374] J. Watt to R. Cullen, 24th April, 1790, ‘Supplementary Volume to Official Descriptive and Illustrated Catalogue of the Exhibition of 1851,’ p. 1475.
[ [375] One day in March, 1802, on the occasion of a strong west wind blowing, when the canal-boats could with difficulty be moved to windward, the steamer took in tow two laden sloops, the ‘Active’ and ‘Euphemia,’ of seventy tons each, from Lock 20 to Port Dundas, Glasgow, a distance of 19½ miles, in six hours.
[ [376] ‘A sketch of the Origin and Progress of Steam Navigation.’ By Bennet Woodcroft. London, 1848.
[ [377] Symington continued to struggle for many years under the burden of debt which he had incurred by his experiments; and though a sum of 100l. was granted him from the Privy Purse in 1824, and 50l. a year or two afterwards, he remained in a state of poverty during the rest of his life. He died on the 22nd March, 1831, and was buried in the churchyard of St. Botolph, Aldgate, London.
[ [378] The following deposition was made on oath by Robert Weir of Kincardine, before Robert Dundas J. P. for the county of Perth, at Blair Castle, on the 23rd October, 1824:—“That, in the year 1801, he remembers of Mr. Symington erecting a boat, and fitting a steam-engine into it, and dragging two vessels along the Forth and Clyde Canal by means of the said steamboat. That the deponent was employed as engine-fireman on board of the said boat. Deposes that the following persons, now living, were also on board, viz., Alexander Hart and John Allen, ship-builders, Grangemouth, and John Esplin and William Gow, shipmasters there. That some time after the first experiment, while the boat was lying upon the canal at Lock 16, it was visited by a stranger, who requested to see the boat worked. That the said William Symington desired the deponent to light the furnace, which was done, and the stranger was carried about four miles along the canal, and brought back. That this stranger made inquiries both as to the mode of constructing and of working the boat, and took notes of the information given him by the said William Symington. That the deponent heard the stranger say his name was Fulton, and that he was a native of the United States of America. That the deponent remembers Mr. Symington remarking that the progress of the boat was much impeded by the narrowness of the canal, to which Mr. Fulton answered that the objection would not apply to the large rivers of North America, where he thought the boat might be used to great advantage.”—From copies of affidavits in the ‘Biography of William Symington.’ By J. and W. R. Rankin, Engineers, Falkirk, 1862.
[ [379] In one of his letters, Bell says—“Fulton came at different times to the country and stopped with me for some time.”—‘Life of Henry Bell,’ p. 74.
[ [380] Cited in Muirhead’s ‘Life of James Watt,’ 2nd ed. p. 426.
[ [381] Boulton to Lord Hawkesbury, 22nd August, 1803. Boulton MSS.