160 ABSTRACTS FOR THE BAROMETER. 
TABLE V.—Monthly Means of the Height of the Barometer minus the Pressure of Aqueous Vapour. 
Month. 20h. 23h, 2h, 5h LES 0. HEE 
Four Hours. 
1841. in. in. in. in. in. 
July 29-092 29-118 29-121 29.114 29-111 
August 29-200 29-167 29-152 29-167 29-171 
September 29-133 29-108 29-084 29-075 29-100 
October 29-099 29-129 29-094 29-106 29-107 
November 29-226 29-281 29-218 29-209 29-233 
1842. 
January 29-402 29-417 29-368 29-369 29-389 
February 29-374 29-390 29-377 29-417 29-389 
March 29-278 29-261 29-237 29-218 29-248 
April 29-750 29-717 29-651 29.628 29-686 
May 29-339 29.314 29-254 29.263 29-292 
June 29-435 29-409 29-399 - 29-376 29-405 
July 29-311 29-288 29-261 29.254 29-278 
August 29-303 29-285 29.288 29-273 29-287 
September 29-316 29-297 29-254 29-250 29-279 
October 29-453 29-446 29-433 29-410 29-435 
November 29.217 29.224 29-214 29-215 29-217 
December 29-338 29-370 29-372 29-395 29-369 
The greatest mean pressure of the dry air occurs in April 1842, the least in September 1841; the range — 
being 0-586, nearly the same as for the moist air. 
TABLE VI.—Mean Height of the Barometer minus the Pressure of Aqueous Vapour, for periods of Three Months, 
for the Summer and Winter Months of 1842, and for the Year 1842. 
. Mean of the 
Period. 20%. 20%, ~ ’ Four Hours. 
1841. | in 
July, Aug., Sept. 29-142 
October, November 29-162 
1842. 
Jan., Feb., March 29-351 
April, May, June 29-508 
July, Aug., Sept. || 29-310 
Oct., Nov., Dec. | 29-336 
29-343 
Jan., Feb., March, | 
Oct., Nov., Dec. \ 
April, May, June, 
July, Aug., Sept. } 
The Year. 29-376 
29-409 
A maximum in the pressure of the dy air occurs in the winter about 235, and in the summer nearer 20" 
than 23). 
A minimum oceurs in the winter between 2" and 54, and in the summer near 5" ? 
The pressure of moist air, Table II., shews the same periods of maxima and minima. 
The mean pressure of the dry air in summer differs much less from that in winter than in the case of moist air. 
