ccxviii GENERAL SUMMARY OF SCIENTIFIC AND 



glish, affirms that it has amounted to less than nothing retrogression. 

 One of the parties interested has clung to the 80,000 trial works at 

 Dover, involving a shaft nineteen feet in diameter, colossal pumping 

 engines, and a submarine driftway seven feet square. Another party, 

 in the railway interest, advocated the exj^enditure of a few thousands 

 at a time for smaller trial works, to make a shaft seven or eight feet 

 in diameter, less pumping power, and as moderate a driftway under 

 the channel as could practically be driven. By this means, it was 

 claimed, the requisite practical knowledge of the difficulties of the 

 work in contemplation could be gained with the minimum of ex- 

 penditure, the sum of 20,000 being named as the maximum amount 

 for which such a shaft could be driven, and a suitable driftway carried 

 under the sea for a distance of a third of a mile, and pumping ma- 

 chinery erected capable of pumping 500,000 gallons per day. The 

 result of this conflict of opinion appears to have been that those who 

 were depended upon to supply the funds needed for the preliminary 

 works have either withdrawn their influence or have held aloof, and 

 matters on the English side have, in consequence, remained prac- 

 tically at a dead lock. 



On the French side, we are iuforaied on the same authority, there 

 has been a quiet and steady onward movement on a small but useful 

 scale. The dredgings of Sir John Hawkshaw on tliat side of the 

 channel were confirmed and enlarged by M. La Vallee and his staft' 

 some time ago. Since September of the year 1875 the English sea- 

 bottom of the channel has been sounded, and additional confirmations 

 and more precise knowledge obtained ; and a boring was commenced 

 and is just finished at Sangatte, about six or seven miles west of 

 Calais. Th'e official rejDort of the French engineers upon these re- 

 sults has not yet appeared, but the following statements afibrd as 

 complete a resume thereof as can be made from extra-official sources 

 of information. The l)oring was commenced at Sangatte, on the 

 upper wdiite chalk, at somewhat less than half its thickness ; it lias 

 penetrated the lower white chalk, and has gone through about six- 

 t3^-six meters of gray chalk, identical in all its distinguishing char- 

 acteristics with the gray chalk on the English coast. It has further 

 penetrated into the gault clay after passing a thin band of dark- 

 green upper greensand ; the total depth of the boring is 133 meters, 

 and the diameter 24 centimeters. As one of the objects of these 

 borings was to ascertain the amount of water that would be likely 

 to be met with in the final operations, the shaft has been lined to a 

 considerable depth with iron tubing of diffierent diameters, let in 

 telescopewise, the annular space between the tubes being filled in 

 with cement, in order that the same might be consolidated and ren- 

 dered water-tight. On this score the results obtained appear to 

 have been quite favorable, the amount of infiltration being quite 

 small, and derived, notvvithstanding the proximity of the sea, from 



