“It may not be improper to mention that Earl Stanhope has lately taken a patent for moving a vessel by steam, but not by wheels. His Lordship has also applied to us for engines; but we believe we are not likely to agree with him, as he lays too much stress upon his own ingenuity.
“We cannot conclude without observing, that were we disposed to enter into any new concern whatever, there is no person we should prefer to Mr. Miller as an associate, being fully apprised of his worth and honour, and admirers of the ingenuity and industry with which he has pursued this scheme.
“Permit me now, Sir, to return you my thanks for your obliging attention to me, and for the trouble you have taken in this affair, and to ask the favour of your presenting Boulton and Watt’s respectful compliments to Mr. Miller.—I remain, dear Sir, &c. &c.,
“James Watt.”[374]
Mr. Miller proceeded no further with his experiments, on which he had already expended a large sum of money. He seems to have lost faith in the applicability of the steam-engine to the propulsion of ships, and reverted to his original idea, as we find him taking out a patent in 1796 for a new kind of flat-bottomed ship, which he proposed to impel during calms by means of wheels worked by capstans; but he makes no mention whatever of the use of the steam-engine.
Symington was greatly disappointed with the result of his experiments. Being without the means of carrying the steamboat further, he feared that all his past labours would prove in vain, and that some more fortunate speculator would carry off the prize that seemed almost within his grasp. The subject was not, however, allowed to sleep. Fitch and Evans were pursuing the invention in America; Rumsey, another American, came over to England in 1788, with a scheme for propelling boats by steam; and Fourness and Earl Stanhope were making experiments in the same direction; but none of them had yet succeeded in constructing a practicable working steamboat. Thus ten more years passed, during which other inventors came forward, took out patents, made their trials, failed, and disappeared.
In the year 1801 Symington had another chance. Lord Dundas, Governor of the Forth and Clyde Canal Company, had been revolving in his mind whether some more expeditious and economical method than horse-power might not be contrived for hauling the boats along the canal; and, being aware of the experiments made by Miller and Symington ten years before, he determined to give Symington’s engine another trial. A boat was accordingly built for the purpose of the experiment, and named the ‘Charlotte Dundas,’ after his Lordship’s daughter. For this vessel Symington contrived a steam-engine of a greatly improved character. It was a direct-acting engine, the steam acting on each side of the piston, after the method invented by Watt, whose patent had now expired; the rotary motion of the paddle-wheels being secured by means of a connecting-rod and crank, instead of by chains and ratchet-wheels, as in the first two boats.
MACHINERY OF THE ‘CHARLOTTE DUNDAS.’
The first trial of the vessel was perfectly satisfactory. After making a trip to Glasgow, she was employed in towing vessels along the canal. She was also occasionally sent down the Frith to bring up ships detained by contrary winds to the canal entrance at Grangemouth.[375]