346 THE ELLESMEKE CANAL. PAKT VIII. 



the Ellesmere Canal and the designing of these gigantic 

 works. He had in the mean while been carefully gather- 

 ing experience from a variety of similar undertakings 

 on which he was employed, and bringing his observa- 

 tions of the strength of materials and the different forms 

 of construction to bear upon the plans under his con- 

 sideration for the great aqueducts of Chirk and Pont- 

 Cysylltau. In 1795 he was appointed engineer to the 

 Shrewsbury Canal, which extended from that town to 

 the collieries and ironworks in the neighbourhood of the 

 Wrekin, crossing the rivers Eoden and Tern, and Ketley 

 Brook, after which it joins the Dorrington and Shropshire 

 Canals. Writing to his Eskdale friend, Telford said : 

 " Although this canal is only eighteen miles long, yet 

 there are many important works in its course several 

 locks, a tunnel about half a mile long, and two aqueducts. 

 For the most considerable of these last, I have just re- 

 commended an aqueduct of iron. It has been approved, 

 and will be executed under my direction, upon a prin- 

 ciple entirely new, and which I am endeavouring to 

 establish with regard to the application of iron." l 



SIDE VIEW OF CAST IRON TROUGH. 



It was the same principle which he applied to the 

 great aqueducts of the Ellesmere Canal now under con- 

 sideration. He had a model made of part of the pro- 

 posed aqueduct for Pont-Cysylltau, showing the piers, 

 ribs, towing-path, and side railing, with a cast iron 



1 Letter to Mr. Andrew Little, Langholm, dated Shrewsbury, 13th March, 

 1795. 



