526 Geological Society. 



states, it ought to contain detritus from the coal-fields which occupy 

 the whole district between Basford and the Derbyshire limestone 

 hills, whereas he has found only one or two small pieces of what 

 might be called jet. He has also never obtained any specimens of 

 magnesian limestone, though that formation occupies almost the 

 whole country to the north-west and north. Mr. Bailey therefore 

 suggests, that the gravel was drifted from a district between the 

 north and east points. 



The mass of these deposits consists of fragments of coarse quartz- 

 ose rock, frequently tinged in a great variety of ways. Many of 

 the pebbles of sandstone are traversed by white veins which project 

 above the general surface : other specimens are rolled portions of 

 quartzose conglomerates, and the greater part of the materials com- 

 posing them appear to have been much worn, before they were in- 

 closed in the cement; but some of the fragments have sustained very 

 little abrasion by removal from their native bed, preserving all the 

 sharpness of recent fractures. Small masses of iron-ore are not of 

 unfrequent occurrence. Mr. Bailey has seen only one specimen of 

 mica-slate. Many fragments of trap are found in these deposits and 

 some of them are of considerable size, constituting the largest blocks 

 in the deposit, and sometimes weighing two or three hundred pounds ; 

 they are often much worn as well as decomposed on the surface. 

 Fragments of porphyry likewise are not rarely met with ; and masses 

 of greenstone, or a compound of hornblende and felspar, are also 

 mentioned by the author. 



No freshwater or marine shells have been discovered in these 

 accumulations. 



Organic remains derived from other deposits are very rare, with 

 the exception of casts of vegetable origin, Mr. Bailey having found 

 only two impressions of shells. Siliceous fragments of stems of 

 Sigillaria and Stigmaria occur in every pit, retaining more or less in- 

 dubitable marks of their origin, and occasionally exhibiting on the 

 surface a smooth, coffee-brown-coloured coating. One specimen in 

 the author's possession, measuring nearly foyr and a half feet in cir- 

 cumference, and weighing about 200 pounds, is stated to retain what 

 appears to be a portion of the original bark. 



A large series of specimens accompanied the memoir, and was pre- 

 sented by the author. 



A letter, dated February 1 840, from Mr. Thompson of Yarrells, 

 near Poole, in Dorsetshire, and addressed to Dr. Buckland, was after- 

 wards read. 



The object of this communication is to give an account of a boring 

 in search of water at the Union Workhouse, Longfleet, near Poole. 



The first land- spring was tapped at the depth of 36 feet, the sur- 

 face of the ground being about 90 feet above low tide in Poole Har- 

 bour. The water was abundant and rose four feet. The next 

 spring occurred at the depth of 127 feet, and others burst forth 

 at 131 feet, 140 feet, 142 feet, 150 feet, 156 feet, 165 feet, 167 feet 

 and 185 feet, from the surface. They all flowed to the same height, 

 and appeared, Mr. Thompson states, to have been fed from the same 



