They might, and certainly would, lose time in making a roundabout of some two or three hundred miles in searching for a wind; but, if they really knew what they were about, they would be sure to catch it at last, and to turn it to their purpose.
From April to October, when the sun's rays fall with greatest effect on Arabia, India, and China, and the several interjacent seas to which these immense countries give their name, the air in contact with them, becoming heated, rises, and gives place to fresh supplies drawn from the equator.

But this equatorial mass of air has had imparted to it by the earth's rotation a greater degree of velocity in the direction from west to east than belongs to the countries and seas just mentioned; and this additional velocity, combined with its motion from the equator, in rushing to fill up the vacuum caused by the rarefaction of the air over those regions intersected by the tropic, causes the south-west monsoon.

"This wind," says Horsburgh, "prevails from April to October, between the equator and the tropic of Cancer, and it reaches from the east coast of Africa to the coasts of India, China, and the Philippine Islands; its influence extends sometimes into the Pacific Ocean as far as the Marian Islands, on to longitude about 145 deg.

east, and it reaches as far north as the Japan Islands." The late Captain Horsburgh thus describes what takes place in the winter months:--"The north-east monsoon," he says, "prevails from October to May, throughout nearly the same space that the south-west monsoon prevails in the opposite season mentioned above.

But the monsoons are subject to great obstructions by land; and in contracted places, such as Malacca Strait, they are changed into variable winds.
Their limits are not everywhere the same, nor do they always shift exactly at the same period." During this last named period, when the north-east monsoon is blowing, viz.