1869.] The Projected Mersey Tunml and RaUway. 183 



The late Mr. Thomas Duncan, then Engineer to the Liverpool 

 Waterworks, stated that he knew well the nature of the rock, which 

 is not very porous. He did not think the quantity of water pro- 

 duced from the rock at Birkenhead and Liverpool would make the 

 tunnel a difficult work of construction, and he did not beheve there 

 would be any difficulty in carrying it through so far as water is 

 concerned. He considered that the " faults " existing in the sand- 

 stone rock, and shown on the geological map, were advantageous, 

 as he had cut through many of them (having excavated in the red 

 sandstone at various points over sixty square miles) and had nearly 

 always found them filled up with a species of concrete, which was 

 perfectly water-tight. In a few instances, however, he had found 

 them fiUed with laminated rock, having a saccharine appearance, and 

 evidently having been subjected to a great heat, and yet water-tight. 



Mr, James Abernethy, C.E., stated that, having been Engineer 

 to the Birkenhead Docks, he had large experience of the sandstone 

 rock, and that the rock under the river is good hard red sandstone 

 rock, of the same character as the rock excavated from the Birken- 

 head Docks, which is a close, compact, strong stone, suitable for 

 building purposes. 



Mr. John Fowler, C.E., stated that in framing his estimates he 

 had well considered the question of possible faults in the rock, and, 

 on the whole, preferred to have faults of the character known to 

 exist in the red sandstone at Liverpool and Birkenhead, as they, 

 being impervious to water, back up and limit in area the water 

 contained in the interstices of the rock. The faults are filled either 

 with clay or with some vitreous material. Mr. Fowler further 

 stated that he considered red sandstone at all times the best 

 material to construct tunnels through. 



Besides the above testimony, there is the further fact that Mr. 

 John Hawkshaw, C.E., F.K.S., proposes to construct a tunnel under 

 the Mersey, near its mouth, where the river is very wide and the 

 character of the rock less certain ; and it is therefore evident that 

 Engineers of eminence are agreed in considering the work of making 

 a tunnel thoroughly practicable, and that at a moderate cost. 



As much doubt has been expressed as to the possibility of 

 driving the heading for any such sum as 20,000^., I would remark 

 that the Trustees have before them a tender from a responsible 

 contractor, who is prepared to undertake to complete the work 

 considerably within that amount, finding all necessary plant and 

 machinery, and giving apjjroved security to the extent of 5000/. 



Again, the chief item in the cost of this work is that of excava- 

 tion, and the Engineers already mentioned, and who gave evidence 

 before the Eeferees, were agreed in considering 9s. a cubic yard an 

 ample price for this work in the tunnel, including all possible con- 

 tingencies, being, in fact, three times the cost of similar work under 



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