1865. j Hull on Water Supply from New Bed Sandstone. 421 



total supply of 200 millions of gallons capable of supplying at the 

 rate of 20 gallons per head ten millions of people, or half the popu- 

 lation of England and Wales. Such a calculation may doubtless be 

 considered rough, and may require considerable modification on 

 various accounts ; but it will serve to show, after making every 

 deduction, that we have, placed within reach, sources of supply which, 

 if not inexhaustible, will certainly prove sufficient for the wants 

 of many generations ; for it is probable that at present not more 

 than fifty millions of gallons are raised from the New Red Sand- 

 stone. 



Some idea of the enormous supply which this formation is capable 

 of yielding from wells advantageously situated, may be gathered from 

 returns of some of the wells now in operation. Amongst the more 

 remarkable is the Green Lane Well, which is situated about two miles 

 east of Liverpool. The details of the works which have been carried 

 on, as kindly furnished to the author by Mr. Duncan, will not be 

 without interest, as they illustrate the connection which exists between 

 increase of supply and increase of depth and diameter of the well, or 

 boring, as the case may be. 



The well was sunk in 1845-6, the surface being 144 feet above 

 the sea-level, and the depth of the well 185 feet ; or 41 below the 

 sea-level. 



At first the yield was 1,250,000 gallons per day. A bore-hole, 

 6 inches in diameter, was then driven to a depth of 60 feet from the 

 bottom of the well, when the yield increased to 2,317,000 gallons. 

 In June, 1853, the supply had slightly fallen off, being 2,303,000 

 gallons, upon which the boring was still further carried down 38^ 

 feet, when the yield increased to 2,689,000 gallons. In June, 1856, 

 the bore-hole was widened, and carried down 10l£ feet farther, when 

 the yield amounted to its present supply of 3,321,000 gallons per 

 day. Now, in these boring operations, we arrive at the following re- 

 sults. In the first boring of 60 feet, the increase was at the rate of 

 17,783 gallons per foot ; in the second, of 38£, the increase was 

 only at the rate of 9,789 gallons per foot ; and in the third only 

 6,277 gallons per foot. It is easy to perceive that any further in- 

 crease would be at a rapidly diminishing ratio with the depth, until a 

 zero point had been attained. 



In 1850, the average supply from seven public wells in Liverpool 

 was 4,216,784 gallons every twenty-four hours.* It is now probably 

 upwards of 5,000,000 gallons drawn from an area of about twenty 

 square miles. The wells of Manchester and Salford, of which only 

 that at Gorton is public property, yield about 6,000,000 gallons, ex- 

 clusive of the well at the works of Messrs. Bailey and Craven, at 

 Agecroft, near Pendleton, where from a well and bore-hole reaching 

 a total depth of 435 feet, it is stated that no less than 5,000,000 

 gallons a day can be raised when the engines are in full opera- 

 tion, f - 



* Mr. K. Stephenson's Eeport. 



t The boring was executed with the machine of Messrs. Piatt and Mather. 

 For an account of the yield of this well I am indebted to Mr. S. C. Hornersharn, C.E., 

 for whom the amount was ascertained in 1859. 



