141 



I have divided the Diluvium or Till into two members, as certain 

 recent discoveries, lately laid by Mr. Smith before the Geological 

 Society, have shown it to have been deposited at two periods, with quiet 

 waters intervening ; and this also adds indefinitely to the already very 

 extended length of time required for the development of these beds. 



Perhaps we will not be far wrong if we conclude that there was once 

 a time when the valley of the Clyde was an arm of the sea, and that 

 its waters eddied around the various eminences which mark the physi- 

 cal geography of Glasgow. Far prior this must have been to the era 

 when the receding waters left the lower reaches of the river, winding 

 through low swampy plains, the broader lagoons and channels of which 

 floated the canoe fleet of the aborigines, afterwards to be embedded on 

 their reedy banks. Equally distant on the other hand must it have 

 been from those still earlier days, when waters, whose bounds were full 

 5(J() feet higher than the present margin of the sea, supported the arctic 

 " Tellina proxima," whose remains the Aii'drie claj's have yielded to 

 modern researches. 



What of the still more ancient epochs, when the luxuriant vegetation 

 of the coal measures was waving on all the central strath of Scotland, 

 from Forth to Clyde, hemmed in on either side by the dark red rocks 

 of the old red sandstone, which had arisen at a stiU more remote date 

 from the profound depths of ocean. And when those rugged crags of 

 conglomerate, with their water-worn boulders, were strewed at the 

 bottom of ocean, there was an older land. In the words of Playfair, 

 " Revolutions still more remote appear in the distance of this extra- 

 ordinary perspective. The mind seems to grow giddj' with looking so 

 far into the abyss of time; we become sensible how much farther 

 reason may sometimes go than imagination can venture to follow." 

 I feel constrained to repeat a remark which I have ventured before to 

 make, that the indefiniteuess of time, which geology requires, is only 

 equalled by the indefiniteness of space which astronomy demands ; 

 and the twain only surpassed by the injinitrj of Him who fills them 

 both with the evidence of His presence and His perfections. 



