It is needless now to give the details of works which, though they excited the wonder of contemporaries, have been far surpassed in magnitude by more recent undertakings. One feature in the Duke of Bridgewater’s canal, however, is too remarkable to be passed over: it is continued on the same level more than three quarters of a mile into the heart of the hill in which the collieries are situated, so that after a short transit in low waggons along the galleries of the mine, the coal is deposited at once in the barges which convey it to Manchester. For a fuller account, we may refer to Phillips’s History of Inland Navigation. In 1762, the Duke of Bridgewater obtained an Act of Parliament, enabling him to continue his canal from Worsley in an opposite direction to Runcorn, in the tideway of the Mersey, so as to establish a perfect water-way between Liverpool and Manchester, unembarrassed by the constant current, and inequalities of flood and drought, which impeded the navigation of the Irwell. In this part of the line several deep valleys, especially those of the rivers Mersey and Bollin, were to be crossed, and this was done without the assistance of a single lock. Brindley’s method of constructing the long embankments, which occurred in some places, was remarkable: he built caissons along the line of its intended course, into which boats laden with excavated soil were conducted by the canal itself, and discharged their contents upon the very spot where the ground was to be raised. Thus the canal, as it were, pushed itself forward; and the labour and expense of transporting these immense masses of earth was greatly diminished. To guard against the total loss of water, and ruin to the surrounding country, which might occur from a breach of these embankments, Brindley contrived stops, which were gates so hung as to lie horizontally near the bottom when the water was at rest, but to rise and close when any current should be produced by the banks giving way, and thus prevent the escape of any water, except that portion near the breach which should be comprised between them. It is hardly necessary to add that the result of this, the greatest undertaking perhaps ever performed by any private person out of his own fortune, has been the realization of an enormous income to the peer who undertook it, and to his heirs.