228 DRIFT DEPOSITS OF MANCHESTER 



Fk;. 4. 



By the side of Upper Brook-street, at the corner 

 of Hughes-street, was formerly seen a large block 

 of Trap Rock, having some of its sides smoothed, 

 and others rugged. Besides the above, there are 

 no doubt many others of less magnitude which 

 have escaped observation. 



On the Origin of the Till. 



When the whole of the Drift phenomena were 

 summarily disposed of by attributing them to the 

 Noachian deluge, little attention had been paid to 

 this deposit, or else its formation could not have 

 been attributed to the same cause that produced 

 the beds of sand and gravel. The action of 

 waves on lines of rocky coast, and the effects now 

 caused by running water, clearly show us how 



