Coniblj ^iatruds. 



By a. p. I. COTTERELL, Assoc. M.Inst.C.E. 

 Read Tuesday^ January 21s^, 1890. 



THE Cornwall Railway, which extends from Plymouth to 

 Falmouth for a distance of QQ miles, was opened in 

 1859 as a broad-gauge single line, though most of the bridges 

 were built to eventually accommodate a double line of broad 

 gauge. The West Cornwall Railway, which joins the Corn- 

 wall line at Truro, and extends to Penzance, was opened in 

 sections. It was originally a narrow-gauge single line only ; 

 but when the Great Western Railway bought it up, they 

 laid down a third broad-gauge rail throughout, so that it 

 is now a mixed gauge. As might be expected from the 

 hilly nature of the country, the Cornish lines are anything 

 but flat. Steep gradients follow one another almost without 

 intermission, and sometimes continue for miles. In the 

 Glynn Valley, between Bodmin and Liskeard, the line rises 

 at the rate of 1 in 60 to a height of about 450 feet, gradually 

 ascending from the level of the River Fowey, till it reaches 

 the top of the hills and disappears over the ridge. As it 

 rises it crosses numbers of side ravines, some deep and some 

 shallow, which are mostly spanned by viaducts, there being 

 of these no less than seven in a distance of four miles. 



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