1820.} Mr. Dalton on Meteorology. 255 



Averages of Mr. G. Walker's Account of Rain in Salford 

 (^Manchester) from 17 S6 to 1793 inclusive. 



Inch. Incorporated with mine. 



January 2-47 2-310 



February 2-75 2-568 



March. ' 2-05 2-098 



April 2-30 2-010 



May 3-51 2-895 



June 3-30 2-502 



July 4-62 3-697 



August 4-78 3-665 



September 4-21 3-281 



October 4-51 3-922 



November 3-30 3-360 



December 5-28 3-832 



Total 43-08 36-140 



Whether we consider the averasces as deduced from Mr. 

 Walker's observations, or from my own, or from the two united, 

 the conclusion is equally obvious ; namely, that the first six 

 months of the year must be considered as dri/ months, and the 

 last six months of the year as 2cet months ; also, that April is 

 the driest month in the year, and that the sixth after, or October, 

 is the wettest, or that in which the most rain falls, in a long 

 continued series of years, in the immediate neighbourhood of 

 Manchester. 



It would be interesting to inquire how far these conclusions 

 apply to Great Britain in general, or to Europe at large, or still 

 more generally to the northern temperate zone. 



In the 4th vol. of the Society's Memoirs, p. 576, is given an 

 abstract or summary of Mr. Hutchinson's account of rain at 

 Liverpool for 18 successive years ; namely, from 1775 to 1792 

 inclusive. The annual average is 34-4 inches. Every one of 

 the first six months yielded less rain (on the average) than any 

 one of the last six months of the year. March was the driest, 

 and October the wettest month in the year. 



In the same volume, p. 580, there are given the results of 16 

 years' observations of the rain at Dumfries, by Mr. Copland, 

 namely, from 1777 to 1793. The annual average was 37 inches. 

 The driest month is April, and next to it Marcli ; the wettest is 

 September, and next to it October ; and each of the first six 

 months of the year is drier than any one of the last six. 



At Chatsworth, Derbyshire, froni the same volume, p. 586, 

 tt seq. I deduce the following averages for 16 years (1777 to 

 1792 inclusive), as per table. 



Here again we see that March is the driest, October the 



