218 DRIFT DEPOSITS OF MANCHESTER 



strata met with in the valley, just below the moor, 

 where Messrs. Bleackley, at their works, bored a 

 considerable depth some years ago. The kind- 

 ness of these gentlemen has enabled me to give 

 the following section : — 



Tarda. 



Sand and Gravel 21 



Till 26 



New Red Sandstone 2 



30 



The range of the deposits is entirely from 

 my own personal observations, without having 

 received assistance from surveyors, or parties 

 engaged in sewering ; and, from the great extent 

 of the space, thickly covered with buildings, exa- 

 mined, it cannot be expected to be particularly 

 exact. It is given as an outline, and can only 

 be completed by careful levelling of the whole 

 district. 



On the Structure of the Valleys and 

 Brook Courses. 



The valley of the Irwell (which is of much the 

 greatest extent) will, on reference to the map and 

 sections, show that it has been cut through the 



