i8 



SCIENTIFIC SURVEY OF YORK AND DISTRICT 



It will be seen that for January there has been a substantial rise both 

 in the mean maximum and mean minimum, resulting in a rise of about 

 two degrees in the mid-temperature. July shows little change, but in 

 the whole year there is a rise of about a degree in the mid -temperature, 

 the main proportion of which is contributed by a rise in the minimum. 

 It is impossible to be certain that the whole of these differences are real ; 

 they may be due in part to the growth of trees or other changes in the 

 environment of the observing station. Also a slight rise in the mean 

 minimum may be expected from the fact that from 1871 to 1899 the 



Table II. — Temperature. 



I (max. -|- min.). 



