40 The Principles of Fruit-growing. 
eastern states in May, 1895;* and most of the 
serious disasters of untimely cold are of this kind. 
These freezes are mostly beyond the reach of man. 
He can only move beyond their limits. But injuri- 
ous frosts may not only be avoided, in many cases, 
by the selection of the location or even of the site, 
but they may sometimes be prevented upon the very 
night when they are expected. 
The chief local determinant of immunity from 
frost is proximity to bodies of water. These bodics 
act as equalizers of temperature. The water holds 
latent heat, and it does not respond quickly to the 
atmospheric fluctuations. It is, therefore, cooler in 
summer and warmer in winter than the adjacent 
land is. The larger and deeper the body of water, 
the greater is this equalizing effect upon the tem- 
perature of the shores. As between the two, great 
depth is more important than great expanse of sur- 
face. Lakes which are only a mile or two wide may 
exert a very profound influence over the adjacent 
*In order to show the natural history of one of these wide-area freezes, 
the following account is given (by E. T. Turner, Meteorologist of the Weather 
Bureau of the Department of Agriculture of the State of New York) concern- 
ing, eauses.which led to the disastrous cold snap of May 13, 1895, in New 
York'state: 
“ For about a week preceding the 12th, the temperature had been very high, 
from 80 to 85 degrees in the daytime and from 50 to 60 degrees at night. The 
temperature of the soil must, therefore, have been considerably higher than 
usual at that time of the year. The conditions which produced the freeze 
were very general rather than local. About the 9th, the pressure increased and 
the temperature fell over the western and central parts of the continent. 
Early on the 11th a large low-pressure or storm area passed eastward over 
Canada, southerly winds flowing into it, giving the high temperature observed 
here at noon of the llth. But after the storm center passed further to the 
eastward we were subject to the cold westerly winds which flowed into the 
depression from the cold high-pressure area in the west, and which continued 
