45 8 ON THE COn GLOMERATE-ROCK 



and beds of sandstone in it, as have been described 

 in the mass at Stonehaven, and it also here rests 

 upon the same species of red sandstone as it does 

 at that place. This red sandstone, at the Burn, is, 

 in its stratification 260 feet thick, and rests upon a 

 clay-porphyry, the bed of which is 220 yards 

 thick. This porphyry is perfectly similar in eve- 

 ry respect to that which has already been descri- 

 bed at Stonehaven. 



At the village of Callender, about 80 miles 

 north-west of Stonehaven, and which is similar in 

 its situation to the Burn, with respect to the 

 Grampians, the conglomerate becomes highly pro- 

 minent and conspicuous. It there forms high 

 mural precipices, which stretch from that vil- 

 lage far to the west. It is at Callendtr vertical in 

 its position, and there, also, it rests upon the same 

 species of red sandstone as it rests upon at Stone- 

 haven, and at the Burn, which are the two other 

 points that I have chosen for description. 



That such vast accumulations of water-worn 

 stones should exist, is perhaps not an extraordina- 

 ry phenomenon ; but that these water- worn stones 

 have every appearance of having been deposited 

 by water, must be generally allowed, and how 

 the conglomerate which they form, comes to be 

 vertical in position, seems to me to be a phenome- 

 non most difficult to explain. That some ex- 

 planations upon this subject have been attempt- 



