160 



Absteacts for the Barometer. 



TABLE V. — ^Monthly Means of the Height of the Barometer minus the Pressure of Aqueous Vapour. 



Month. 



20''. 



23''. 



2'-. 



SI-. 



Jlean of the 

 Four Hours. 



1841. 



in. 



in. 



in. 



in. 



in. 



July 



29092 



29-118 



29-121 



29.114 



29-111 



August 



29-200 



29167 



29-152 



29-167 



29-171 



September 



29- 133 



29-108 



29-084 



29075 



29-100 



October 



29099 



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 



29314 



29-254 



29263 



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 



in. 



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. 



Period. 



20'>. 



ash. 



2'>. 



5^. 



Mean of the 

 Four Hours. 



1841. 



in. 



in. 



in. 



in. 



in. 



July, Aug., Sept. 



29-142 



29-131 



29119 



29-119 



29-128 



October, November 



29-162 



29-205 



29156 



29-157 



29-170 



1842. 













Jan., Feb., March 



29-351 



29-356 



29-327 



29-335 



29-342 



April, May, June 



29-508 



29-480 



29-435 



29-422 



29-461 



July, Aug., Sept. 



29-310 



29-290 



29-268 



29-259 



29-282 



Oct., Nov., Dec. 



29-336 



29-347 



29-340 



29-340 



29-341 



Jan., Feb., March, ^ 

 Oct., Nov., Dec. J 



29-343 



29-351 



29-333 



29-337 



29-341 



April, May, June, \ 

 July, Aug., Sept. j 



29-409 



29-385 



29-351 



29-340 



29-371 



The Year. 



29-376 



29-368 



29-342 



29-339 



29-356 



A maxinmm in the pressure of the dty air occurs in the winter about 23^, and in the summer nearer 20'' 

 than 23'\ 



A minimum occurs in the winter between 2^ and 5^^, 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. 



