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are prosecuting their great work of passing under the Severn 

 by means of a tunnel more than four miles in length. From a 

 geological point of view the workings are of great interest, as 

 owing to the disturbed condition of the strata, the section of 

 rocks to be penetrated constitutes an unknown problem not 

 very easy of solution ; and as the ultimate success of the scheme 

 depends largely on the nature of the section, every yard of the 

 work is of great and increasing interest. 



The party was received by the engineer of the works, who 

 was at much jDains to explain the mode of operation, the suces- 

 sion of beds, and the nature of the obstacles to be anticipated. 

 The succession of beds at that time passed through was given 

 as follows : — 



Total 205 feet. 



The " shoot" is kept clear of water by a powerful pumping 

 apparatus, which discharges a large quantity of brackish or 

 saline water, the saltness of which increases with the flow of 

 the tide, shewing thereby infiltration from the Severn. In the 

 deepest part of the river-bed there is a depth of 60 feet of water 

 at low tide, and 100 feet at high tide ; an amount of pressure 

 which, combined with the probability of "faults" to be met 

 with in the strata, suggests cause for reflection, if not for appre- 

 hension. But the engineer had no fears. It is without doubt 

 a bold work, and one which wiU be watched with great interest 

 by the public, as well as by scientific men. Mr. Ltjct drew 



