276 Mil. G. V. VERNON ON THE MEAN 



or, arranging the months in their order of amount_, we 

 have : — 



October i'5o 



April 1*67 



September I'Sg 



May I "9 1 



January 2*02 



June 2'o6 



March 2-17 



July 2-35 



November 2*37 



August 2*6 1 



December 3-01 



February 3*26 



One point in this seems somewhat curious ; and that is, 

 that the wettest and driest months should be liable to about 

 the same changes of temperature ; the distribution seems 

 very irregular, months widely apart coming next one an- 

 other as regards this element of temperature. 



At the bottom of Table II. I have given the values of 

 the probable variation of mean temperature for each 

 month, computed from my own observations for the 

 twenty years ; and as the late Manuel J. Johnson gave 

 similar values, computed from Dalton^s observations, 1794 

 to 18 18 (Radcliffe Observations, vol. xv. 1854), I annex 

 them for comparison. 



Dalton. Old TraflPord. 



25 years, 179410 18 18. 20 years, 184910 1868. 



o o 



January +27 +i'8o 



February i-8 3*50 



March 16 i"93 



April 2*1 i'49 



May 1*9 170 



June 1-6 I '84 



July I -8 2*09 



August I '2 2*48 



September i-6 i"68 



October 17 1*33 



November 2*0 2*11 



December +i-8 +2*68 



There are evidently great discrepancies between the two 

 series of values, which it is quite out of my power to ex- 

 plain ; but reference to the monthly means for Old Trafford 



