OBSERVATIONS ON THE FALL OF RAIN. 179 
The rain at Bolton for this year was one inch, 
or 1-49th below the mean, the mean rain being as 
stated above to the end of 1840—49=th inches. 
No observations having been taken upon the 
depth of rain falling upon the drainage ground of 
the reservoir, the information furnished does not 
enable us to ascertain what proportion of the 
whole was impounded. Of course the rain must 
have exceeded the water actually collected and 
discharged. 
During the past year, many observations have 
been taken upon an extensive tract of land, ad- 
joining the drainage ground of the Turton and 
Entwistle reservoir, for the express purpose of 
ascertaining many of the points now under con- 
sideration. The facts there observed will pro- 
bably supply the deficiency, in the information 
afforded by that reservoir. 
On the 13th January last year (1843) a rain 
gauge was placed on land contiguous to a reser- 
voir of the Bolton Water Works Company, for 
supplying the town with water. The reservoir 
