CHAP. IV. ROCHDALE CANAL. 147 



room, in many parts, for only the water-way, the turn- 

 pike road, and the little river Calder in the bottom of 

 the ravine. At some points, where space allowed, there 

 were mills and manufacturing establishments jealous of 

 their water-supply, which the engineer of the line had 

 carefully to avoid. It was also necessary to provide 

 against the canal being swept away by the winter's 

 floods of the Oalder, which rushed down with immense 

 violence from Blackstone Edge. Large reservoirs had to 

 be carefully contrived to store up water against summer 

 droughts for the purposes of the navigation, as well as 

 to compensate the numerous mills along the valley 

 below. One of these, fourteen feet deep, was dug in a 

 bog on Blackstone Edge, and others, of large dimen- 

 sions, were formed at various points along the hill-route. 

 But as these expedients were of themselves insufficient, 

 powerful steam-engines were also erected to pump 

 back the lockage water into the canal above, as well 

 as into side-ponds near the locks to serve for reser- 

 voirs, and thus economize the supply to the greatest 

 extent. No more formidable difficulties, indeed, were 

 encountered by George Stephenson, in constructing 

 the railway passing by tunnel under the same range 

 of hills, than were overcome by Mr. Rennie in carry- 

 ing out the works of this great canal undertaking. 

 The skill and judgment with which he planned them 

 reflected the greatest credit on their designer ; and 

 whoever examines the works at this day even after 

 all that has been accomplished in canal and railway 

 engineering will admit that the mark of a master's 

 hand is unmistakably stamped upon them. The navi- 

 gation was completed and opened on the 21st of Decem- 

 ber, 1804; and we need scarcely add that it proved of 

 immense service to the trade of Yorkshire and Lanca- 

 shire, bringing important manufacturing districts into 

 easy and economical connection with each other, 

 enabling cheap fuel to be brought to the doors of the 



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