292 Reports and Proceedings. 



Tlie journals of bores referred to had been collected exclusively by- 

 Mr. James Croll, during the latter part of last summer, before leaving 

 for Edinburgh to join the staff of the Geological Survey of Scotland. 

 These might be arranged into three divisions. First, — those bores 

 which i^rove that breaks occun'ed in the formation of the Boulder 

 clay, during which great beds of such water-formed materials as 

 sand, gravel, or mud were laid down upon true ice-made debris 

 alternately several times in succession, showing thereby that the 

 glacial epoch was not uniform in character or duration, but was 

 broken by comparatively warm periods, during which water instead 

 of ice determined the character of the deposits. Some of the facts 

 which proved this were very remarkable. One bore at Larkhall had 

 in section — brown till, 8 feet ; sand, gravel, and mud, 36 feet ; 

 brown till and boulders, 17 feet; sand, 3^ feet; brown till and 

 boulders, 26 feet; mud and sand, 31 feet; brown till and boulders, 

 6 feet ; from which it is evident that the water periods were not 

 short, when 36 feet in the first, and 31 feet in the third were de- 

 posited during their continuance. Another bore in the Mains of 

 Garscadden gives — first, boulder clay, 78 feet ; then follow various 

 beds of sands, gravels, and clays, 127 feet ; then succeed enough of 

 Boulder-clay at the bottom to give an inter-glacial character to the 

 127 feet of aqueous sediment resting upon it. Another bore, in 

 the farm of Millichen, gives a greater variety. In it there are, 

 first — brown clay and stones, assumed to be Boulder-clay, 17 

 feet; various beds of mud, sand, and gravel, 150 feet; brown clay 

 aud stones, 30 feet ; gravel and sand, 6 feet ; a thin bed of Boulder- 

 clay, 6J feet ; another great water period, represented by 66 feet of 

 sandy mud, and then at bottom Boulder-clay, 82 feet ; — in all, 355 

 feet, which is certainly a remarkable group of deposits. Another 

 bore sunk close to West Millichen farm house is 200 feet in depth, 

 and consists of five beds of Boulder-clay interlaced with four beds 

 of sand, one of which is 45 and another 53 feet in thickness. Upon 

 the evidence furnished by these bores, the inference might be justly 

 drawn, that the glacial epoch was not uniformly glacial throughout, 

 but was broken up by warmer periods, during which the ice became 

 water, and instead of Boulder-clay, the undoubted debris of ice, sand, 

 gravel, and mud, the forms which water-made drift assumes, was 

 the only sediment possible. 



The next division of bores reveal the existence of a deep trough 

 or hollow, stretching from the valley of the Clyde, near Bowling, 

 through Garscadden, the Haughs of Balmore, the valley of Kelvin, 

 and round by the south-eastern end of the Campsie hills, into the 

 valley of the Forth, by Falkirk. The first indication of its exist- 

 ence is very curious. At Duntocher, the surface sand was cut into 

 by the workings of a pit, belonging to Mr. Dunn, at a depth of 306 

 feet, whereupon the sand rushed into the pit with such rapidity 

 that the miners with the greatest difiiculty escaped with their lives. 

 This proves that the surface strata at Duntocher is 306 feet deep. 

 The next intimation of its existence is from a bore made by Messrs. 

 Merry and Cunninghame, on the farm of Drumry, half-a-mile west 



