298 Wisconsin Academy of Sciences , Arts and Letters. 
son became northeast with a slight rise in temperature instead 
of northwest with a cold-wave. 
The chief damage caused by cold-waves in this section is 
thru their overtaking and freezing perishable merchandise 
which has been shipped during the preceding warm weather. 
Fruit, vegetables, canned goods and liquids of all kinds may 
be .seriously damaged by very cold weather. For this reason 
shippers of such products in the large cities watch weather 
conditions very closely during the winter months and often 
hold back their shipments until the temperature is more favor¬ 
able. 
Anyone whose business or work is liable to injury from ex¬ 
treme cold can with advantage watch, during periods of un¬ 
seasonably warm winter weather, for the conditions which pre¬ 
cede the cold-wave. A storm, as shown on the weather map, 
over the Great Lakes or Northwest, will usually be followed by 
cold weather. One who does not have access to the weather 
map may often obtain advance knowledge of a cold-wave by 
closely observing local atmospheric conditions and watching 
for those which indicate the passage of a storm area. Thus, 
with southerly winds of any strength, rain or snow and un¬ 
usually warm weather for the season, colder weather may be 
expected in 24 hours. Also low barometric pressure, equivalent 
to a sea-level value of 29.8 inches or less, indicates the presence 
of a storm which will be followed by colder weather. When the 
pressure falls much lower (29.5 inches or less, sea level) a cold- 
wave almost invariably follows,, of severity in proportion to the 
depression of the barometric reading below normal. 
The Chief of the Weather Bureau, Willis L. Moore, attrib¬ 
utes much of the physical and intellectual excellence of our 
nation to the invigorating effect of the coM-wave. To a person 
in good health the rapid temperature change is not necessarily 
disagreeable, and the human system receives a certain stimula¬ 
tion, both mental and physical, from the coldness and dryness 
of the air. With its approach foreseen and provided for, the 
cold-wave may well be considered beneficial rather than detri¬ 
mental to the welfare of mankind. 
