Vesey Dee aft 
Ati (Fae LL), AKLAS Lp 
‘THE 
AMERICAN JOURNAL OF SCIENCE, 
[THIRD SERIES.] 
Art. XX VIII.— Contributions to Meteorology; by Et1as Loomis, 
Professor of Natural Philosophy in Yale College. Twenty- 
second paper. With Plate V. 
Areas of high pressure. Their magnitude and direction of move- 
ment. Relation of areas of high pressure to areas 
of low pressure. 
In several former papers I have examined the form and mag- 
nitude of areas of high pressure, the position of the major axis 
of the isobars, the direction and velocity of their movement, and 
the low temperature which accompanies them—the laws of the 
' wind’s motion within these areas—the circumstances under 
which areas of high pressure originate, and the relations which 
they bear to areas of low pressure. This examination has been 
made for the United States by the aid of the Signal Service 
maps and the published volumes of the Signal Service observa- 
tions; and it has been made for Hurope by the aid of Hoff- 
meyer’s Weather Maps. It was found that areas of unusually 
high pressure sometimes extend from the Pacific Ocean to the 
Atlantic; and stretch northward far beyond the limits of the 
United States. The maps of the United States Signal Service 
are therefore not large enough to exhibit satisfactorily the 
phenomena of areas of unusually high pressure, and especially 
to exhibit their relations to areas of low pressure; and the same 
is true of Hoffmeyer’s charts of the Atlantic Ocean and Kurope. 
I have therefore extended this examination to the maps of the 
AM. JOUR. So a tee Srries, Vou. XXXIII, No. 196.—ApRit, 1887. 
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