56 The Principles of Fruit-growing. 
ones are. That is, what may be gained by atmos- 
pheric drainage may be more than overcome by the 
coldness of elevation. The table (page 55) from the 
New York Meteorological Bureau*, compares the 
monthly average temperatures of high and low sta- 
tions. The high stations give, with but two slight 
exceptions, a lower reading than the low stations do, 
but the differences are least, as a rule, in the win- 
ter months, when the effects of atmospheric drainage 
are apt to be least marked. 
Thermometer readings taken upon the slope of 
East Hill, at Ithaca, New York, during January and 
February, 1897, also show the lower average tempera- 
tures of very high lands.t The top of this hill is 
about 400 feet above the valley. Six thermometers 
were placed along its slope, No. I. being at the 
foot of the hill, and No. VI. at its top. Tempera- 
tures taken at night would probably have shown 
more marked differences. It is probable, however, 
that if observations were made at night in still wea- 
ther in spring or fall, between the valley and lands 
from fifty to one hundred feet above it, the higher 
lands would have given the higher figures, in con- 
sequence of the settling away of the cold air. It 
is well known, for example, that ravines along a fruit 
plantation often carry away the cold air and _ save 
the fruit from light frosts, and also that planta- 
tions opposite the mouths of gullies are likely to 
suffer. The Ithaca figures now follow: 
* Fifth Ann. Rep, Meteor. Bureau, N. Y. 388. 
+ Made for me by my student, S. L. Sheldon. 
