W. N. W., or even N. W. by W. will not suffice), there is not an
immediate rise of the barometer corresponding in rapidity and extent with
the fall, and frequently none during the first twenty-four hours of
bright, fair weather. Let the reader, if he has access to a barometer,
note this fact, for it is obvious and conclusive.

Finally, there are other atmospheric conditions to which the barometric
changes are obviously due:

1st. The counter-trade is of a different _volume_, at different times,
over the same locality, and hence a difference in the normal elevations of
the barometer.

2d. It is at a different _elevation_, at different times, over the same
locality. It was so found by the investigations of the Kew Observatory
Committee referred to; has been so found by other aeronauts, and may
readily be seen by a careful, practiced observer.

It is highest, with a high barometer, in serene weather, when a storm is
not at hand; and can sometimes be plainly seen to ascend when a
considerable volume of N. W. wind is blowing in beneath, and elevating,
simultaneously, the trade and the barometer.

Opportunities occur every year, when the northern edge of the dissolving
stratus-cloud is attenuated, and the storm is clearing off in the N. W.,
with wind from that quarter, and a rising barometer, when its gradual
elevation may be observed to correspond with the _volume_ of that wind.

3d. During storms, with a low barometer, the _trade_ and the _clouds run
low_. This, too, is clearly observable, especially when the stratus-cloud
passes off abruptly, very soon after the rain ceases. In such cases the
barometer will remain depressed for a considerable time, unless another
storm supervenes speedily, or the wind sets in from the N. W.

4th. The _trade, in a stormy state, moves faster_ than when in a normal
condition. This is observable during the partial breaks which frequently
occur in storms, and at other times. It is also inferable from the more
rapid progress of the more intense center, and other intense portions of
storms, and the consequent greater depression of the barometer, under such
centers or intense portions. (See the storm of Professor Loomis.) It is
obvious, also, from the greater rapidity of progress attending the more
intense and violent storms which all investigations discloses.

These simple facts explain all the phenomena:

1st. The trade stratum is a continuous unbroken sheet, and its descent
must displ