And Description of the GorbaU Gravitation Water Co.'s Works. 223 



pose that the heat of the city, or some other local cause, occasions an 

 absorption of the ruin-drops as they are falling through the stratum of air 

 immediately above the city. 



Of the quantity of rain falling in this neighbourhood, about one-third 

 part is lost by evaporation, absorption, and other causes ; the other two- 

 thirds can be retained and made available for useful purposes, such as 

 water-power, or the supplying of large towns with water. This is now so 

 well understood, that water-works for the supply of the public are erect- 

 ing in many places throughout Great Britain, upon the principle of 

 collecting, and making available, the quantities of rain which fall 

 throughout the year, and which would otherwise pass off in floods direct 

 to the sea. 



In 1846, an Act of Parliament was obtained by the Gorbals Gravita- 

 tion Water Company, for supplying the inhabitants of Gorbals, Govan, 

 and other places in the neighbourhood, with water, by gravitation, from 

 works to be erected on the estate of Upper Pollock, in the parish of 

 Mearns ; and since then these works have been progressing with great 

 rapidity towards completion ; during a great part of last summer, no fewer 

 than from eight hundred to one thousand men have been employed upon 

 them, in raising the embankments, building the tanks and filters, and in 

 other departments connected with the works. The works, I am happy to 

 say, are now very nearly completed, and in a very short time the inha- 

 bitants of the south side of the river will have an abundant supply of 

 pure water. 



The source from which this water is to be obtained is the Brock Burn, 

 which drains an area of about 2800 acres, and the annual fall of rain in 

 that neighbourhood, for the last ten or twelve years, has been ascertained 

 by Mr. Mather to be 55 inches, two-thirds of which, or 37 inches, could 

 be made available ; but supposing that we can only collect 30 inches out 

 of the 55, it is easy to ascertain what quantity a depth of 30 inches of 

 water over an area of 2800 acres would be. It amounts to about 305 

 millions of cubic feet, or 1906 millions of gallons, which is a sufficient 

 supply for a population of 270,000, allowing each individual to consume 

 twenty gallons daily. For the purposes of the company, however, it is 

 not at present necessary to construct more than two reservoirs, which will 

 contain about fifty millions cubic feet. On the supposition that these 

 will bo filled three times in the year, (which is considerably below what 

 may be expected,) that would givo 150 millions cubic feet, or a supply 

 of twenty gallons daily to each of a population of 133,000 or about double 

 the present number of the inhabitants of Gorbals. 



These calculations are not hypothetical, and are rather under than 

 over the result to bo expected ; sufficient proof of which we have from 

 Paisley, and other works of a similar kind already erected, and which 

 have been in operation. 



Through the kindness of Mr. Stirrat of I who was, I believe, 



Vol. TL— No. 4. 3 



