6 LE. Loomis—Results derived from an examination of the 
because the area of the observations was not Pig po! Bs oe 
tended. The mean value of the high barometer on the ea 
side was 80°42 inches, and the mean distance 1,033 miles; on 
the west side the values were 80°31 inches and 977 miles. If 
the area of the observations had been sufficiently extended 
towards the north, it is presumed there would sometimes have 
been found three areas of high barometer within a distance of 
1,000 miles from the locality where the storm originated. On 
Hoffmeyer’ s storm charts we frequently find three areas of high 
barometer and occasionally four areas of high barometer sur- 
rounding an area of low vpn sa 
tendency of the air towards an intermediate point, and the 
currents thus set in motion are deflected to the right by the 
earth’s rotation, whence results a diminished pressure over the 
central area. is diminished recta causes a still stronger 
inward flow of the air, which results in a still greater ea 
sion of the barometer. Sinise the air shicahies in on all s 
towards this area of low barometer, the area tends to ssdieten 
an oval form, which may become sensibly circular if the winds 
are very violent, and the wee force resulting from this 
revolving motion causes a still further fabio of the bar- 
ometer. This partial vacuum would be soon filled, and the 
inward movement of the air would sane wor it not for an 
upward motion by which the inflowing air escapes. The air in 
its upward motion, eg ae: with it a large amount of aqueous 
vapor, is cooled, and its vapor is condensed, producing rain. 
'The heat which is liberated in the condensation of this vapor 
causes a further expansion of the air, and increases the force of 
the inward movement of the wind. Rain is then one of the 
circumstances which increases the force of a storm, and it 
invariably attends. storms when they have aM! to consider- 
able _ as is shown by the rain-fall m column 5th 
the table on page 2. This table chicrpten shows a large rain- 
fall whenever the storm is so situated as to permit observations 
on its eastern side; but when the center of the storm passes 
beyond our stations of observation, the observed rain- 
fall rapidly diminishes. See Nos. 1, 9, 10, 11, 28, 34, 36 
and 37. 
I have shown in my 7th paper, pp. 14, 15, that an area of 
of considerable m 
low barometer agnitude may be formed and 
continue for several a with vay little rain ; but in these 
cases the barometer was never observed to fall as low as 29°25 
rei ree: it will be’ sioniaieds that some rain was invariabl 
ed barometer 
RE Pee isi. est Sine ee 
enever:the: fell below 29-4 inches, an 
