^8 A DEEP SECTION IN OLD MARKET STREET. 



usually high rise of the tide, which at Cumberland basin frequently 

 exceeds 30 feet. 



The splendid section depicted in the accompanying lithograph, 

 is in a part of Bristol that is most characteristic and instructive. 



The first 10 feet is ordinary made ground lying upon 13 feet of 

 marls, more or less sandy. Gravel is, however, not so constant as 

 at the Hotwells, Cumberland basin, and other parts of the city, 

 but sufficiently so, to cause a connection to be formed between 

 the water of the surface wells and that of the tide, the level of the 

 well water rising and falling with that of the tidal water. The 

 next 97 feet pass through a soft reddish sandstone, which is 

 succeeded by harder sandstone with white veins, mixed with 

 nodules and hard blocks of the coal measures. 



The remaining 145 feet of the shaft passes through dark coal 

 shales. These when first brought to the surface are nearly black, 

 but on consequent exposure and consequent drying, change to a 

 light drab and easily fall to powder from want of a proper binding 

 consistency. These shales differ much in their degree of hardness, 

 some being very soft, whilst others are stony and almost nodular. 



On reaching the depth of 300 feet, a bit of coal was found, and 

 a bit of real though impure coal was brought to the surface. Through 

 the kindness of Mr. Rogers, the samples before you were given 

 me from the depths of 37, 130, 131, 152, 1^5, 18 j, 186, 200, 242, 

 270, and 300 feet respectively. They have now been placed in 

 our excellent Museum, so that should any one at some future 

 time be interested he can consult them. 



