AMERICAN 
JOURNAL OF SCIENCE AND ARTS. 
[THIRD SERIES.] 
e. 
> 
Art. 1.—Oontributions to Meteorology, being results derived from 
an examination of the Observations of the United States Signal 
Service and from other sources ; LiAs Loomis, Professor 
of Natural Philosophy in Yale College. Eleventh paper. 
With plates I and IL 
[Read before the National Academy of Sciences, Washington, April 15, 1879.] 
The Winds on Mt. Washington compared with the winds near the 
level 
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In my last Article I gave some reasons for believing that 
areas of low pressure sometimes result from a circulation of the 
surface winds which does not extend to the height of 6,000 
feet. In order to investigate this subject more fully, I selected 
from the published volumes of the Signal Service observations 
all those cases in which the direction of the wind on Mt. Wash- 
ington differed at least 90° from that at each of the stations, 
Burlington, Boston, and Portland, Me. The number of these 
cases was 507. Three-fifths of these cases occurred when the 
wind on Mt. Washington was from the west or northwest, and 
more than four-fifths of them occurred when the wind on Mt. 
Washington was from one of the points N., N.W., W. or S.W. ; 
and at the same time the wind at the neighboring surface sta- 
tions was generally from one of the points S., S.E., E. or N.E. 
As this Table, if accompanied with the details necessary to 
render it intelligible, is too large for publication, I have adopted 
a different standard of selection, and have taken all those cases 
in which the barometer at Portland, Me., fell as low as 29°6 
inches, This list has already been given in my tenth paper, 
page 9, except that I have added the cases found in the volumes 
of observations since published for January, February and 
Am. Jour. eee Series, Vou. XVIII, No. 103.—Juny, 1879. 
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