AND THE RATE OF MORTALITY. 305 



Annual rate of mortality per cent, in 

 Lancashire. Cheshire. West Eiding. 



1855 2'68o ^■197 2*223 



1856 2'464 2*048 2'2I2 



1857 2*628 2-269 2*368 



1858 2*719 2*267 2*491 



1859 2*454 2*169 2396 



i860 2*371 2*173 2*360 



1861 2*592 2*164 2*321 



1862 2*560 2*246 2*';64 



1863 2*629 2396 2*575 



1864 2*718 2*300 2*656 



1865 2*832 2*328 2*667 



1866 3*016 2*538 2*684 



1867 2*683 2*252 2*443 



Taking the means for the eight years 1855-62, and the 

 five years 1863-67, we have 



Average annual rate of mortality per cent, in 

 Lancashire. Cheshire. West Riding. 



1855-62 2*558 2*191 2*342 



1863-67 2*775 2*363 2*605 



Differences 0*217 0-172 0*263 



These numbers show that the average rate of mortality 

 in Lancashire, Cheshire, and the West Riding was de- 

 cidedly greater during the five years of dry springs and 

 summers with wet autumns and winters, than during the 

 eight years when the seasons were of an opposite character. 

 The difi'erences are equivalent to an increase of 8*4 per 

 cent, in the number of deaths in Lancashire, 7*8 per cent, 

 in Cheshire, and 11 '2 in the West Riding, — the mean 

 amount of increase being 9*1 per cent., which, in Lanca- 

 shire alone, represents an increase of more than seven 

 thousand in the total number of deaths in one year. 



Observations of rainfall were commenced at the Gorton 

 station of the Manchester Water- works in 1847 ; ^^^ ^^' 

 Wilson having kindly furnished me with copies of the 

 monthly amounts for the eight years 1847-54, I have 

 grouped them in six-monthly periods, as I had done the 



SER. III. VOL. IV. X 



