Discussion on the Proposed Channel Tunnel. 59 



time to time ; the moving blocks could be taken up, one at a 

 time, for examination, and relaid. There is no insuperable 

 difficulty, or even serious difficulty, in getting at any part 

 of the thing whenever it may be necessary. 



As regards preliminary experiments, there would be no 

 serious difficulty — the expense would be less than that of a 

 heading-boring — in sending out half-a-mile of tube and sinking 

 it in the place where the water is 900 feet deep. Moor it and 

 leave it there for a year. I believe it would be found at the 

 end of a year all right. One piece of it moored is the same as 

 any other piece. You can get your tackle arranged as you find 

 best, and all these things could be worked at before the final 

 estimates for the tunnel were made. On these accounts, and 

 the greater cheapness and immensely greater rapidity of con- 

 struction, such a scheme is infinitely preferable to the uncer- 

 tainties involved in tunnels bored through rocks. Even if you 

 have bored a hole, one hole is a very uncertain criterion of 

 what may happen within 50 feet of that hole. 



Sir William Quartus Ewart, in reply to the Chairman, 

 said that nothing had been done since the meeting in the Town 

 Hall, at which Mr. Barton had put forward his scheme, and no 

 further communication had been received from that gentleman 

 upon the subject. 



Mr. E. N. MacIlwaine (Mechanical Engineer) said : — I wish 

 to say a few words against the underground tunnel. I have had 

 experience in Queensland of sinking two deep wells, 1660 and 

 1300 feet, and both these wells gave an enormous quantity of 

 water. The pressure at the surface in the case of the 1660 feet 

 well was 64 lbs. per square inch. An Artesian spring might be 

 struck in sinking one of these tunnels, and if so the best thing 

 would be to fill up the tunnel and leave it. 



Mr. John Brown said : — There is one special reason why, as 

 I think, Mr. Maxton's scheme is to be preferred, viz. — because 

 the calculations in it are based on known quantities, whereas 

 the other schemes include a large number of unknown quantities. 

 We know for instance the properties of the water in which 



