he north-easterly monsoon is produced, very much resembling
in its effect, as it strictly does in its cause, the ordinary
trade-wind of the Atlantic and Pacific oceans.

This is a very general view of what may be called the great monsoons
of India; but there are many variations in different places, all of
which are so readily explained by the foregoing theory, that they form
by no means the least interesting branch of the subject, or the least
satisfactory of its illustrations.

One of the most extensive of these varieties, though of a less general
and sweeping character than those which blow in the Arabian sea and
bay of Bengal, is found in a very remote part of the world. "From
October to April this north-west monsoon prevails between the
north-east part of Madagascar and the west coast of New Holland; and
it is generally confined between the equator and 10 deg. or 11 deg. south
latitude, but subject to irregularities." This westerly wind is
evidently produced by the air drawn actually from the equator towards
the slower moving latitudes of the earth, by the rarefaction of the
air to the southward when the sun is near the tropic of Capricorn.
"The south-east monsoon predominates from April to October in the
space last mentioned, and in some places reaches to the equator." In
this case, the slow moving air near the southern tropic is brought, as
in the ordinary case of the south-east Trade wind, to the quick-moving
parts of the earth's surface.

The following remark of Horsburgh's, in describing the monsoons, is
extremely valuable, and assists to explain Hadley's theory of these
matters:--"The parts where the north-west and the south-east monsoons
prevail with greatest strength and regularity are in the Java sea, and
from thence eastward to Timor, amongst the Molucca and Banda islands,
and onward to New Guinea;" for it will be obvious to any one who
inspects the globe, on reading this passage, that there occurs in the
neighbourhood of the spots alluded to a powerful cause for the
strength and regularity of the monsoons. The enormous island, or
continent, as it might almost be called, of Australia, may well be
supposed to act the part of a heater from October to April, when the
sun is so nearly over it. During that period the equatorial air is
drawn to the south, along the intermediate seas, amongst the Moluccas
and other Spice islands, so as to produce a strong and steady
north-westerly monsoon. Of course, the oppos