256 Mr, Dalton on Meteorology. [Aciitfi, 



wettest, and all the former six months drier than any one of the 

 latter. 



By combining the 10 years' observations of Dr. Campbell, of 

 Lancaster (Memoirs, iv. p. 264 and 691), we obtain similar 

 results nearly. March is the driest, and August the wettest 

 month at Lancaster. But 10 years is too short a period to 

 obtain true means. I have the rain at Lancaster for a subsequent 

 period of 10 years (1802 — 1811), furnished me by my friend 

 John Ford, jun. Esq. of Ellel ; which hkewise gives March for 

 the driest, but October for the wettest month of the year. 



In the Annales de Chimie et de Physique (vol. viii. 1818), 

 there is an account of rain at Viviers, lat. 44° 29' N. long. 2° 2' 

 E. of Paris, by M. Flaugerges. The monthly means for 40 

 years' observations (from 1777 to 1818) are stated, from which 

 it appears that February is the driest month in the year, and 

 October the wettest. The annual average is 34 inches (French). 

 The year 1801 was the wettest in that period, yielding 48 inches 

 (French), and 1779 was the driest, yielding 20 inches 7 lines>. 

 Viviers, which is in the S.E. of France, has, however, some 

 essential differences from Great Britain in regard to rain. There 

 the months of July and August are among the driest ; the only 

 months distinguished for heavy rain are September, October, 

 and November ; while April and May yield each more than the 

 monthly average. 



I have collected the Royal Society's account of rain at Lon- 

 don for 28 years, ending in 1806, and find the averages to stand 

 as under ; also those of Luke Howard, Esq. for a subsequent 

 period of 12 years, ending with 1818, made in the vicinity of 

 London. These united are as per table. 



The fall of rain at Kendal for five years (1788—1792) was 

 published in my Meteorology ; since that time the account has 

 been continued by my brother for 18 years, with which he has 

 favoured me ; I have obtained also two years further from good 

 authority, making in all 25 years' rain. The monthly averages 

 I have deduced as per table. 



I deduced the average rain at Paris from observations 

 published in the Journal de Physique for the last 15 years, as 

 per table. 



The average rain at Glasgow for 17 years (1801 — 1818) was 

 deduced from a paper in the Annals of Philosophi/, vol. xii. 

 p. 377. 



