432 A TOPOGRAPHICAL 



is no wonder, that an object, so curious in itself, and of such na- 

 tional importance, should have attracted general attention. 



The Duke of Bridgewater, having found by experience the utility 

 of these inland navigations, extended his views to Liverpool; and 

 obtained, in 1762, an Act of Parliament for branching his canal to 

 the tide-way in the Mersey. This part is carried over the river 

 Mersey and Bollan, and over many wide and deep vallies. Over 

 the vallies it is conducted without a single lock ; and across the 

 valley at Stretford, through which the Mersey runs, a mound of 

 earth, raised for preserving the water, extends nearly a mile. In 

 the construction of this mound Mr. Brindley displayed his mecha- 

 nical genius, by rendering the canal itself subservient to his design, 

 and by bringing the soil, necessary for his purpose, along the canal 

 in boats of a peculiar form, which were conducted into caissoons 

 or cisterns ; so that on opening the bottoms of the boats, the earth 

 was deposited where it was wanted, and the valley was thus ele- 

 vated to a proper level for continuing the canal. Across the 

 Bollan the ground was raised by temporary locks, formed of the 

 timber used in the construction of the caissoons just mentioned. 

 In the execution of every part of the navigation, Mr. Brindley dis- 

 played singular skill and ingenuity ; and in order to facilitate his 

 purpose, he produced many valuable machines. His economy and 

 forecast, in every part of the work, deserve to be particularly no- 

 ticed, and they are peculiarly discernible in the stops or flood- 

 gates, that are fixed in the canal, where it is above the level of 

 the land. These stops are so constructed, that if any of the banks 

 should give way and occasion a current, the adjoining gates will 

 rise merely by that mption, and prevent any other part of the 

 water from escaping, besides that which is near the breach between 

 the two gates. 



Encouraged by the success of the Duke of Bridgewater's under* 

 takings, a subscription was entered into by a number of gentlemen 

 and manufacturers in Staffordshire, for constructing a canal through 

 that county, in pursuance of a scheme which had been suggested 

 some years before ; and Mr. Brindley was engaged to make a sur- 

 vey from the Trent to the Mersey. Upon his report that a canal 

 for connecting the two rivers was practicable, application was made 

 to Parliament, in 1765, for an Act to this purpose, whieh was ob- 

 tained in the same year. 



This canal, which, by its planner, was ingeniously termed the 

 Grand Trunk, (in allusion to the main artery of the body, from whence 



