Mr. R. Etheridge, F.R.8. — Silurian Rocks in Serfs. 287 



" Two of the trials have been some time in progress by the New 

 Biver Company — one at Turnford, near Cheshunt, and the other at 

 Ware, near Hertford. Both these important borings and extensions 

 were undertaken by the New Biver Company for the purpose of 

 obtaining a larger supply of pure water from the Chalk, and for 

 settling the question of the existence or non-existence of the Lower 

 Greensand in Hertfordshire. To a considerable extent the desire and 

 anticipation of the Company have been realized through large sup- 

 plies from their deep penetrations into the Chalk, this being especially 

 the case at the Turnford deep well, near Cheshunt. 



" The presence, however, of the Lower Greensand below the Gault 

 in Hertfordshire has long been problematical; but, knowing that 

 usually it is a source of extremely pure water and in considerable 

 quantities, the New Biver Company undertook, with great public 

 spirit, the completion of the two deep borings named, through the 

 Chalk and Gault. They were quite aware of the probability or 

 possibility of finding some Palaeozoic rock under their trials in Hert- 

 fordshire, and, unfortunately for the deeper supply of water, such has 

 proved to be the case, owing to the absence of the Lower Greensand 

 at Ware (one of their stations), and the occurrence of the partly 

 anticipated more ancient rocks, upon which they now find the Gault 

 immediately rests, without the intervention of the Lower Greensand. 



" It is well known how much interest is attached to the question 

 of the extension of the older formations under the overlying or 

 newer rocks of the south-east of England ; this interest is now 

 intensified through the Ware boring by the discovery of one of the 

 oldest formations in the British Islands immediately beneath the 

 Gault and at the depth of 800ft. At this depth I have to announce 

 the presence of the Upper Silurian rocks (the Wenlock Shale), richly 

 fossiliferous, dipping at an angle of 40 cleg., but to which point of 

 the compass is not at present known. I believe this delicate matter 

 will be ascertained by the engineers of the New Biver Company — a 

 question of the utmost importance in determining the strike or 

 bearing of the older strata at any depth. Fresh interest is now 

 attached to the Turnford boring, the diamond crown being now low 

 down in the Gault at 980ft. 



" So spirited and costly an undertaking to seek for pure water 

 for the supply of the metropolis is, indeed, highly judicious and 

 important on the part of the New Biver Company. We must not 

 too hastily complain of the want of public spirit, when every effort 

 is made to obtain, even at great cost, an element so important to the 

 sanitary condition of the people. In this the New Biver Company 

 have not failed in intuition or purpose, and to their enterprise is 

 due the solution of another geological problem. 



" May 16. BoBERT ETHERIDGE." 



Note — Since the above letter was written to the Times, we have 

 received from Mr. Etheridge the names of the fossils found in the 

 cores of AVenlock rock at the bottom of the bore-hole at Ware. We 

 hope to receive from him, for our next Number, a more detailed 

 notice of the probable Physical Geography and extension of these 



