402 MR. JOSEPH BAXENDELL 



that a shallow stratum of the lower and comparatively 

 clear atmosphere, supplies as much rain as a densely 

 clouded, and much deeper stratum in the higher regions. 

 As these remarkable results may raise doubts as to the 

 general correctness of the methods of observation, which 

 have been used to .determine the quantities of rain at 

 different heights, I may here mention an important fact, 

 for which T am indebted to my friend Mr. Binney, F.R.S. 

 In descending the shafts of deep coal mines, Mr. Binney 

 has observed that the drops of water which drip from the 

 upper part of the shaft increase to an extraordinary size 

 during their descent to the bottom. Evidently the same 

 principle is here in operation as in the case of a rain-drop 

 falling through the atmosphere, and Mr. Binney^ s obser- 

 vation affords a valuable confirmation of the general accu- 

 racy of the results of the observations which have been 

 made to determine the rain-fall at different elevations. 



That the whole amount of a fall of rain is not derived 

 from the direct condensation of vapour at the time that 

 the fall takes place, is apparent from other considerations 

 than those which depend upon the different quantities of 

 rain at different heights. It is supposed by some meteoro- 

 logists that the mild temperatures of the higher latitudes 

 of western Europe are due to the heat which is liberated 

 by the condensation of vapour during the frequent pre- 

 cipitations of rain which take place on or near the coasts ; 

 but if this view were correct, the mean temperature of 

 rainy days ought to be considerably greater than the mean 

 temperature of the year. 



A discussion of the Greenwich observations for the 

 years 1852, 3, and 4, and of the Oxford observations for 

 1855, 6, and 7, with reference to this point, has given the 

 following results : 



