Lo wen 
General Physics. 143 
(7.) First Report on Meteorology ; by James P. Espy. 
This report consists chiefly of maps of the United States, exhibiting 
the direction of the wind, state of the barometer, thermometer, &c., on 
various days in January, February and March, 1843. There are twen- 
ty nine of these maps, which contain a vast amount of valuable infor- 
mation. They clearly indicate. the proper course to be pursued if we 
would arrive at a complete knowledge of the laws of storms. Several 
important generalizations deduced from these observations, accompany 
the report. ‘The following are some of them. 
Storms in the United States travel from west to east; they are ac- 
companied with a depression of the barometer near the centre of the 
storm ; they travel about 36 miles per hour; in great storms, the wind 
for several hundred miles on both sides of the line of minimum pres- 
sure, blows towards that line, directly or obliquely. ‘The force of the 
wind is in proportion to the suddenness and greatness of the baromet- 
ric depression. In all great and sudden depressions ef the barometer, 
there is much rain or snow ; and in all sudden and great rains or snows, 
there is a great fluctuation of the barometer.* Many storms are of 
great and unknown length from north to south, while their east‘and west 
diameter is comparatively small, There is generally a lull of wind at 
the line of minimum pressure, and sometimes a calm. When the wind 
changes to the west, the barometer generally begins to rise. ‘There is 
generally but little wind near the line of maximum pressure, and on 
each side of that line the winds are irregular, but tend outwards from 
that line. The fluctuations of the barometer are generally greater in 
the northern than in the southern parts of the United States, and great- 
er in the eastern than in the western parts.7 - 
(8.) Magnetical and Meteorological Observations made at Washing- 
ton; by Lieut. J. M. Gituiss. 8vo., pp. 648. 
The instruments used in these observations were a declinometer and 
dip circle by Sms, a barometer, several thermometers, hygrometer, 
rain gauge, &c. The magnetic observations embrace two years, from 
July, 1840, to June, 1842 
* ‘The mean declination for 1840-1, was 1° 20’ 12-7 W. 
gs Ks 1841-2, * 1° 23! 569 
* Annual variation, 3! 44-2 
” ‘The minimum declination for each day occurs at 8h. 6m. A. M.— 
' Maximum es “ “ Ss 
A secondary minimum occurs . |. . 946 = * 
maximum “ : ‘ ot ee 
i. 
“ *'Phere are some remarkable cases of great rains with little ‘motion of the ba- 
rometer. ’ 
+ We should like to see the evidence of the second part of this statement. 
