engelmann’s table op MEANS AT ST. LOUIS. 
75 
field (or the mean of several if they can he had) to the monthly means of the stationary barom¬ 
eter. I add, therefore, my monthly means for the last fourteen months. But the observations 
made west of the Rocky mountains cannot he referred to my barometer at all. It is hardly 
necessary to add—what everybody who is in the habit of observing the barometer knows—that 
observations made in the forenoon, principally from 8 to 10 o’clock a. m., are generally higher, 
and those made in the afternoon, principally between 2 and 4 o’clock, are mostly lower than 
the average of the day. The noon observations come nearest the mean of the day. The barom¬ 
eter, at least in the Mississippi valley, is usually highest with westerly and northwesterly winds, 
and lowest with southerly and southeasterly winds. It is mostly higher, hut much more irreg¬ 
ular, in winter, and lower, hut more regular, in summer. 
Mean barometric elevation of barometer E. at St. Louis, 482 feet above the Gulf. 
Table of means corrected for temperature. 
June, 1853.... 29.466 
July, 1853. 29.483 
August 1853. 29.431 
September, 1853. 29.474 
October, 1853. 29.538 
November, 1853. 29.601 
December, 1853. 29.508 
January, 1854. 29.577 
February, 1854... 29.507 
March, 1854... 29.459 
April, 1854. 29.444 
May, 1854. 29.334 
June, 1854. 29.418 
July, 1854. 29.491 
G. ENGELMANN. 
St. Louis, September, 1854. 
The discrepancy found to exist by Dr. Engelmann in the Bunten barometers after our return 
from California did not exist as between themselves up to the termination of the exploration 
in July, and must have arisen from some cause on our homeward journey, and is disregarded, 
therefore, in the discussion. 
Horary variations of the barometer in California. 
1. In the elevated portions of the interior. 
Hour. 
Inch. 
5 a. m. 
. —.007 
5 a. m. 
. —.005 
6 a. m. 
. +.012 
7 a. m. 
. +.025 
8 a. m... 
. +.030 
9 a. m. 
. +.035 
10 a. m. 
. +.040 
11 a. m. 
. +.045 
12 m. 
. +.015 
1 p. m. 
. —.005 
Hour. 
Inch. 
2 p. m. 
. —.025. 
3 p. m.. 
. —.030 
4 p. m. 
. —.035 
5 p. m. 
. —.033 
6 p. m.. 
. —.025 
7 p. m. 
. —.015 
8 p. m. 
. —.005 
9 p. m. 
. +.008 
10 p. m. 
. +.015 
11 p. m. 
. +.013 
