EF. Loomis—Contributions to Meteorology. 257 
Northern Russia. A small area of low pressure which pre- 
vailed over Southwestern Hurope, and a low area which ap- 
parently prevailed near the northern boundary of Asia may 
have contributed to this effect. For the four following days, 
the phenomena remained nearly the same, but the pressure 
near the center of the high area increased, and on the 6th the 
isobar of 30 inches included almost the whole of Asia, extend- 
ing into the Pacific Ocean on the east, and it also included a 
large part of Europe. On the 7th there was a slight diminu- 
tion of pressure which continued during the three following 
days, and this was apparently the effect of a low area in North- 
ern Asia which drew off the air from the Northern side of the 
high area, and the center of the high area was thereby carried 
southward. On the 10th the pressure on the north side was 
restored, and the center of the high area moved northward, but 
the barometer did not commence rising until the following day. 
On tlre 11th the barometer began to rise, and now the small low 
area which had prevailed over Southern Hurope since Dec. 2d 
was obliterated by the advance of a high area from the Atlantic 
Ocean. On the 12th the barometer rose somewhat higher ; at 
most places the wind had subsided almost to a calm, and the 
air was generally less humid. On the 18th the rise in the 
barometer was more decided, and now a great change of tem- 
perature which for several days had been steadily advancing 
from the eastward, had reached the center of high pressure. 
On the 14th the isobar 81:0 inches included an area about 
1400 miles in length and 800 in breadth, and the pressure 
attained its maximum between the 16thand 17th. On the 19th 
the isobar 31:0 inches apparently included an area 3400 miles in 
length, and 1450 miles in breadth. Throughout the central por- 
tions of this high area, the air was dry, the wind subsided almost 
to a calm, and the sky was generally cloudless. After the 17th 
the barometer began to fall, the temperature rose somewhat, the 
humidity of the air increased, and there was some cloudiness, 
but the clouds were reported light. This decline of pressure 
may have been dueto the fact that the outward movement of 
the air from the high area had become greater than the supply 
from the low areas before named, two of which had now become 
extinct. After the 20th the low area which had prevailed over 
the Atlantic Ocean advanced eastward, and on the 14th the 
isobar 29:0 inches included the whole of Norway, by which 
means the pressure throughout Kurope and Western Asia was 
greatly reduced. At the same time there was some increase of 
temperature, but the rise of the thermometer indicated by Table 
V on the 20th and 21st, was due mainly to a change of position 
of the high center. The thermometer at Barnaul still continued 
30 degrees below zero of Fahrenheit. 
