Many other improvements Brindley introduced into the mechanical arts. But about this time his thoughts were drawn towards a larger sphere of action by the resolution of Francis Duke of Bridgewater to cut a canal from his coal mines at Worsley to the town of Manchester, distant about seven miles. This scheme is said to have been before conceived by one of that nobleman’s predecessors: but that circumstance does not detract from the honour due to the great perseverance and resolution displayed in the execution of his plan. Divesting himself of the splendour which usually belongs to his rank, he devoted his large revenue almost entirely to his favourite undertaking: resisting the temptation to borrow money, lest he should involve himself and his successors in irremediable difficulties, in case of the failure of an undertaking which, from its novelty, no man living could assert to be certain of success. At the same time having selected Brindley as his engineer, on good experience of his skill and talent, he placed a noble confidence in him; and, without fear or distrust, devoted his energy and fortune to work out the magnificent design which the genius of his coadjutor had planned. As the difficulties to be overcome were very great, so there was little experience to guide the projectors. Navigable rivers indeed had been improved, and those which were not navigable by nature had been made so by pounding up their waters with locks and dams: but of canals, properly so called, this was the first constructed in England. That it might be perfect in its kind, it was resolved to preserve a level, and avoid locks altogether: but to effect this obstacles were to be overcome, such as never had been surmounted in England,—obstacles which had always been considered insurmountable. Navigable tunnels were to be cut, long and large mounds to be carried across valleys, and in the line which finally was adopted, an aqueduct bridge of three arches, nearly fifty feet in height, and including the embankments on each side, five hundred yards in length, was to be carried over the river Irwell. This part of the scheme being generally considered wild and extravagant, Brindley, to justify himself to his employer, desired that the opinion of another engineer might be taken. This was accordingly done: but the second, on being conducted to the spot where it was intended that the aqueduct should be made, exclaimed, “I have often heard of castles in the air, but never before was shown the place where any of them were to be erected.” But the Duke of Bridgewater’s confidence in Brindley was not to be shaken, and the bridge was undertaken and finished within less than a year.