30 HULL SCIENTIFIC AND FIELD NATURALISTS’ CLUB. 
of the Geology of Yorkshire,” 1829, in which the outcrop appears 
to be about 380 square miles. In my estimate I eliminated that 
portion of the chalk which underlies the clays of Holderness, and 
which being near the sea and Humber would probably be found 
to be impregnated with salt, and therefore unfit for drinking 
purposes. Assuming the chalk exposed to the heavens to be 240 
square miles, and each cubic foot of saturated chalk to contain 
2 to 24 gallons of water, z.e., 20 to 25 lbs. in weight, this would 
produce about 250,000 tons per square mile for each foot in 
depth. Taking the depth of the fresh water bearing chalk below 
the minimum water-line, or line of complete saturation to be 
100 feet, this would amount to 25 millions of tons per square 
mile, or 6,000 millions of tons for the whole area. Reducing this 
estimate one-half, and concluding that two-thirds of the remainder 
runs to waste in the Hessle Whelps and on our foreshores north 
of Bridlington, we have left 1,000 millions of tons. If one 
million of persons be dependent upon it, and require 30 gallons 
per day fer capita, then the present supply would last 20} years. 
But it would not be possible to drain the whole of the water out 
of the chalk, and so the esimate must be further reduced. | What 
is left shows that we have a supply which will last us many years. 
At the time I gave my lecture several towns in England were 
bordering on a water famine, and through the kindness of my 
uncle, Mr. Frederick Slade, c.£., of Beckford, who is a member of 
the Institute, and also a member of the Meteorological Society, I 
was enabled to place before our members information which 
could not be procured apart from many hours of hard work on 
Symon’s Meteorological Journals. I give the results here, and, 
despite the wet weather we have since experienced, they will yet 
arouse more than ordinary interest unless two or more wet years 
restore the balance. Leaving out of consideration the year 1887, 
which was the driest year since 1788, the mean rainfall for 
fifteen places in England (so chosen as to embrace all parts of it) 
was carefully and accurately ascertained. This contrasted with 
the mean rainfall at the same places for the last decade (1888 to 
1897) shows that the mean rainfall for the ten years is in all cases 
below the general average. The total deficiency for the decade 
is as follows:—London, 22 inches; Salisbury Plain, 22°3” ; 
Penzance, 7°7"; Bristol (Clifton), 29°8”; Birmingham, 29°2” ; 
Beckford (Gloucestershire), 41°5” ; Norwich, 12” ; Pembroke, 39” ; 
Oswestry, 58”; Sheffield, 35:7”; Doncaster, 13°7”; Hull, 179” ; 
Liverpool, 24” ; Manchester (Denton Reservoir), 249” ; Barnsley, 
251". The average deficiency for these fifteen places is 26°85”, 
and corresponds to 607,503 gallons, or 2,712 tons of water per 
acre, 
ee 
a 
