52 



THE SEVERN TCJNNEL. 



lost in clearing the foundations oE the gravel hoforc wotIv 

 could bo started again. The gravel nearly half filled the 

 holes every tide, and was of a size sometimes equalling that 

 of a man's double fist. 



Now, as these holes were well above the low- water mark, 

 while the Shoots channel in the main current is seventy feet 

 lower, and as the bulk of the griivol, particularly the larger 

 stones forming it, must run in the deepest channels, it was 

 evident that very large (Quantities of heavy gravel must run 

 up and down these channels with every spring-tide. 



It thus became clear to the writer of this paper that, sup- 

 jjosing only the strata were hard enough to resist the scour- 

 ing action of the water, any joint or fissure in the rock must 

 be choked with this gravel, sand, and fine mud so completely 

 that no Severn water could possibly get down to any work- 

 ings below, and that, therefore, the deep low-water channel 

 of the Shoots— which is, without doubt, in rock more than 

 sufficiently hiird for the purpose — might be tunnelled under 

 with perfect confidence. This has since been entirely borne 

 out by the facts, and there is now positively no leakage of 

 Severn water. 



Having thus convinced himself of the perfect practica- 

 bility of a Tunnel under the Severn, the writer, at the time, 

 mentioned his idea to Mr. Leonard T3ruton, the very abl(^ 

 secretary of the railway then being constructed. He told 

 him that ho thought a Tunnel might bo made under the 

 Severn for half a million, exclusive of the in-shoro n.p- 

 proaches. Mr. ISrutou's reply was—" Then, that is the 

 right scheme." 



From that time the writer bcga,n to make further investi- 

 gations, by taking very numerous souTulings in tlus Shoots, 

 and by putting down trial borings, all of which fully con- 

 firmed his previous observations. He was, of course, greatly 



