inds, rain, and storms. Occasionally, from
causes not yet fully explained, north and south periodical winds break
in upon them, such as the Northers which rage in the Gulf of Mexico.

There are many curious facts connected with the Trades, and with the
Monsoons, or trade-winds turned back by continental heat in the East
Indies, the Typhoons, the Siroccos, the Harmattans, land and sea
breezes and hurricanes, the Samiel or Poison Wind, and the Etesian.
The Cyclones, or rotary hurricanes, offer a most inviting field for
observation and study, and are an important branch of our subject. But
we are obliged to omit the consideration of these topics, to be taken
up, possibly, at some other opportunity. The theory of the Cyclones
may be justly considered as original with our countryman, Mr.
Redfield. Colonel Reid, Mr. Piddington, and other learned Englishmen
have adopted it; and so much has been settled through the labors of
these eminent men, that intelligent seamen need fear these storms no
longer. By the aid of maps and sailing-directions they may either
escape them altogether, or boldly take advantage of their outward
sweep, and shorten their passages.

We have yet to ascertain the causes of the many local winds prevailing
both on the ocean and the land, and which do not appear to be
influenced by any such general principle as the Trades or the
Monsoons.

The force of air in motion gives us the gentle breeze, the gale, or
the whirlwind. At one hundred miles an hour it prostrates forests. In
the West Indies, thirty-two pound cannon have been torn by it from
their beds, and carried some distance through the air. Tables of the
velocity of winds are familiar to our readers.

Let us next advert to the connection of the atmosphere with Vapor and
Evaporation. The vapor rising from the earth and the sea by
evaporation, promoted by dry air, by wind, by diminished pressure, or
by heat, is borne along in vesicles so rare as to float on the bosom
of the winds, sometimes a grateful shade of clouds, at other times
condensed and gravitating in showers of rain. Thus it enriches the
soil, or cools the air, or reflects back to the earth its radiated
heat. At times the clouds, freighted with moisture, present the most
gorgeous hues, and we have over us a pavilion more magnificent than
any ever constructed by the hand of man. These clouds are not merely
the distilleries of rain, but the reservoirs of snow and hail, and
they are the agents