showing the equatorial limits of both
Trade-winds, deduced by the late Captain James Horsburgh, hydrographer
of the East India Company, from the observations of 238 ships. These
tables show very clearly the effect of the absence or presence of the
sun in shifting the limits of the Trades, drawing them after him, as
it were. The presence of the sun in either hemisphere obstructs
considerably the regularity and strength of the Trade-winds in that
hemisphere, and _vice versa_.

The great difficulty experienced in making the outward-bound voyage
commences after the ship has been deserted by the north-east Trade,
for she has then to fight her way to the southward across the region
of Calms and Variables. But as these Variables blow generally from the
southward and westward, from a cause afterwards to be explained, it is
obvious enough why this part of the homeward voyage is always more
easily made than the outward passage. These southerly breezes, which
are met with in the Variables, blow at times with considerable force,
and greatly perplex the young navigator, who, trusting perhaps to some
of the erroneous published accounts, not unnaturally reckons upon
meeting the regular Trade-wind, blowing, as he supposes, from the east
near the equator, not from the south; still less is he prepared or
pleased to find it blowing from the south-westward.

This troublesome range, intervening between the two Trades, varies in
width from 150 to more than 500 miles. It is widest in September, and
narrowest in December or January. I now speak more particularly of
what happens in the Atlantic. In the wide Pacific, far from land,
fewer modifying circumstances interfere with the regular course of the
phenomena, than in the comparatively narrow sea formed by the opposite
shoulders of Africa and South America.

Calms, also, are met with in this intermediate region, or purgatory of
the outward-bound voyage, and occasionally violent tornados or
squalls, which in a moment tear away every rag of canvas from a ship's
yards. For several hours at a time, also, rain falls down in absolute
torrents. Even when the weather clears up, and a fresh breeze comes,
it is generally from the southward, directly in the outward-bound
navigator's teeth. He must have patience, however, and strive to make
the most of it by keeping on that tack by which most southing is to be
gained. It is now, I believe, generally held to be the best practice
to place the ship betwee