[Sidenote: Mr. Symington and Mr. Taylor.] About this time Symington, who was employed at the lead mines at Wanlockhead, had succeeded in constructing a small steam-engine of a new description, originally intended for the purpose of propelling wheeled carriages, which he patented June 5th, 1787.[54] His specification, accompanied by drawings, relates, 1, to heating the cylinder of a steam-engine; 2, loading the piston; 3, placing a fire round the cylinder; 4, a boiler; and, 5, “when rotatory motions of whatever kind are wanted, two ratchet wheels will be placed upon one or the same axis in such manner that, while the engine turns forward one wheel, the other will be reversed without impeding the motion or diminishing the power so as to be ready to carry on the motion by the time the other wheel begins to be reversed.” As this engine was considered suitable for the purpose Mr. Taylor had in view, Symington[55] undertook to perform the work and Mr. Miller agreed to employ him. When completed it was mounted in an oak frame and placed on the deck of one of Mr. Miller’s pleasure-boats, a vessel 25 feet long and 7 feet wide, with two wheels, to be tested on Loch Dalswinton. The engine performed its work beyond their most sanguine expectations, driving the vessel at the rate of 5 miles an hour, though the cylinders were only 4 inches in diameter. After being used in cruising about the lake for a few days, the engine was removed from the boat and conveyed to Mr. Miller’s house, where it remained as a piece of ornamental furniture for a number of years. The accounts which appeared in the Scottish newspapers at the time[56] state that the first experiment was made on the 14th November, 1788, and with such success that it was resolved to repeat it on a larger scale upon the Forth and Clyde Canal. A double engine with cylinders 18 inches in diameter was consequently ordered to be built at Carron Iron Works, and, in November of the following year, it was fitted on board of another of Mr. Miller’s vessels and tried on Dalswinton Loch. As, however, the floats of the wheels gave way, it was not until the 26th of December, by which time stronger wheels had been procured, that an opportunity was afforded for fairly testing the capabilities of this engine. From the accounts in the local papers of the period[57] the experiment appears to have answered thoroughly, though made under many disadvantages; a speed having been obtained of from 6½ to 7 miles an hour, which, in the words of the report, “sufficiently shows that a vessel properly constructed might accomplish 8, 9, or even 10 miles an hour easily.”[58]