03 



of the strata, ou the West side, must be from two to three 

 hundred feet, at least, below the corresponding strata on the 

 East side ; and, in the valley between Broad Green and 

 Huyton, the up-throw of the coal measures, on the East 

 side, must be from two to three thousand feet above the 

 corresponding strata on the West side. I have here to 

 observe that the highest sides of the faults, as they are 

 termed, do not always preserve the same elevation in their 

 course North and South; for, in the secondary or transverse 

 lines of fracture, faults of a very considerable difference of 

 height also abound. 



This crossing of faults, as is well known, performs 

 important offices in the working of mines, and those of coal 

 more particularly. The joints, or fractures, in the coal 

 measures being frequently filled up with stiff retentive clay, 

 and the impervious nature of the strata, together dam the 

 water in the surrounding strata back from the posts, as they 

 are termed, in which the workings are carried on. Engines 

 for pumping water, of comparatively small power to what 

 they should be, were the strata continuous, are thereby 

 sufficient to keep the workings clear of water. Thus, 

 in an economic point of view, these faults are, to us, of 

 great importance, and the bearing which they have on the 

 question more immediately under our consideration will 

 shortly be shewn. 



The configuration of the surface of the district is, in a 

 great measure, due to those lines of fracture and of elevation; 

 hence we have the varieties of hill and valley, in a miniature 

 form certainly as compared with other districts. These, as 

 I have frequently had occasion to notice in this society, run 

 conformably with the primary lines of fracture North and 

 South, and retain a kind of parallelism throughout. To the 

 down- throw of the strata in the bed of the Mersey, Liver- 

 pool and other thriving communities on its banks entirely 

 owe their existence. 



