Sound, for hours
before it is felt upon either shore; and when all is calm in the evening
on land, and often before the moon forms a halo or circle in the milky
condensation of the approaching storm, or any sign of condensation is
visible, the breaking of the waves upon the shores may be heard. Doubtless
this may be observed on the shores of the Atlantic at other points.

This power of attracting the surface atmosphere from bodies of water like
the ocean and the great lakes, will account for two apparent anomalies,
mentioned by Mr. Blodget in a valuable and instructive article read to the
Scientific Convention, in 1853, regarding the annual fall of rain over the
United States.

First--the influence of mountains in extracting the water from the
atmospheric currents which pass over them, is well known and readily
explainable. Mr. Blodget, however, found that the source of our rains,
whatever it might be, when it reached the Alleghanies, was so far
exhausted of its moisture that those mountains extracted less from it than
fell to the westward, by some five to ten inches annually; and that the
fall of rain upon them was less than upon the Atlantic slope eastward of
them, to the ocean. This does not accord with observation elsewhere, but
is easily explained. As the storm approaches the ocean, it attracts in
under it the surface atmosphere of the ocean, loaded with vapor,
condensing in the form of fog and scud, as it becomes subject to the
increasing influence of the storm. Although the scud and fog would not of
itself make rain, it aids materially in increasing the quantity of that
which falls through it. The drops, by attraction and contact, enlarge
themselves as they pass through, in the same manner as a drop of water
will do in running down a pane of glass which is covered with moisture.
The small drop which starts from the upper portion of a fifteen-inch pane,
will sometimes more than double its size before it reaches the bottom. _It
is by this power of attracting the surface atmosphere, which contains the
moisture of evaporation, under it, and inducing condensation in it, that
the moisture of evaporation which rarely rises very far in the atmosphere
is made to fall again during storms and showers._ This attraction of a
moist atmosphere from the ocean accounts for the excess of rain on the
east of the Alleghanies, compared with its fall upon them. So the great
valley of the Mississippi is comparatively level, and less of