The Relation of Ice Storms to Trees. 
By Joun W. HarsHBERGER, Pu. D. 
The year 1902 was noted for two exceptionally destruc- 
tive ice storms that visited the region lying contiguous 
to Philadelphia. One of these storms occurred on Friday, 
February 21st, and the other on Saturday, December 13th. 
The storm of February 21st was accompanied by high winds 
and did an irreparable damage to the fruit, forest and 
shade trees. The storm of December was noted for the 
larger amount of ice formed, but the damage was not so 
great, because there was very little wind to break off the 
limbs that were weighted down with the ice. 
Meteorologically speaking, regions of strongly variable 
temperature are subject to occasional winter storms in which 
the precipitation, occurring as rain, freezes as soon as it 
touches any solid body, such as the branches of trees, tele- 
graph wires or the ground. This happens when the ground 
and the lower air have been made excessively cold during a 
spell of clear anticyclonic weather, when a moist upper cur- 
rent in advance of an approaching cyclone’ brings clouds 
and rain. New England is particularly subject to such 
storms and in the winter of 1886, three ice storms occurred 
in January and February, but this was exceptional. They 
were all accompanied by northeast winds with surface tem- 
perature at or a little above freezing, while slightly higher 
temperatures prevailed on Mount Washington.? Although 
+A cyclone, in the meteorologic sense, is an area of low pressure with 
inflowing spiral winds, seldom of destructive strength on land. 
2 Davis, W. M., Elementary Meteorology, p. 204, 1894. 
(345) 
