ON THE CIRCULATION OF UNDERGROUND WATERS. 121 



grains. 



Chloride of sodium 4-83 



Sulphate of soda 7"33 



Carbonate of soda 7"35 



„ of lime 9"77 



„ of magnesia 5-29 



34-57 



The following section of a well and boring at Seedly Print-Works, given 

 by Messrs. Binney and HuU, is of value, as showing that while the Upper 

 Permian series attain a thickness of 128 feet, the Lower Permian Sandstone 

 is but 12 feet 6 inches, though at CoUyhurst, 2| miles to the east, it has 

 expanded to a thickness of 250 feet. 



feet. 



1. Drift. Boulder-clay 61 



2. Trias. Soft red sandstone 139 



3. Upper Permian. Marls, sandstone, and beds of limestone .... 128 



4. Lower Permian. White rock, red sandstone 12| 



5. Coal-measures 30 



370| 



The whole of the Permian formation, as proved by various wells and 

 borings, is subject to great variation of thickness, due probably to uncon- 

 formability. 



In the borough of Salford Mr. Binney has recorded a large number of 

 borings for water at the factories and printing works ; one of these, at Messrs. 

 Dewhurst Dawson's Croft, Greengate, gave : — 



feet. 



1. New Bed Sandstone. Ked and streaked sandstone 180 



2. Upper Permian. Eed marls, with 4 thin beds of lime- 



stone and one of grit 210 



3. Lower Permian. Soft bright red sandstone, bottom not 



reached. 



In a boring at the brewery near Albert Bridge, the following sequence 

 occurred : — 



feet. 



New Bed Sandstone 470 



Upper Permian. Red marb with limestone 120 



Lower Permian. Red sandstone and clay 10 



These borings point to the Lower Permian Sandstone as the source of the 

 water in the deep wells of the Salford district. 



At Ordsull a boring 460 feet in depth failed to reach the base of the New 

 Red Sandstone, and the water at the bottom of the bore became so salt that 

 the work was given up : this is probably the only instance of salt water 

 being met with in the sandstones of the Trias, though it commonly occurs in 

 the marls. 



East of the Manchester coal-field is a tract of New Red Sandstone, 2 

 miles in width, in which is situated the Gorton Waterworks, where a well 

 210 feet is capable of yielding 600 gallons per minute, notwithstanding the 

 greater part of the drainage-area is covered with impermeable Boulder- 

 clay. 



