that, on the contrary, those which precede the land-breeze are, in the Java Sea, generally of shorter duration, accompanied by a heavy atmosphere, and that there is also an evident difference between the conversion of the land breeze into the sea breeze, and of the latter into the former. Even as the calms vary, so there appears to be a marked difference between the changing of the monsoons in the spring and in the autumn in the Java Sea. As soon as the sun has crossed the equator, and its vertical rays begin to play more and more perpendicularly upon the northern hemisphere, the inland plains of Asia, North Africa, and of North America are so heated as to give birth to the south-west monsoons in the China Sea, in the North Indian Ocean, in the North Atlantic, and upon the west coast of Central America: then the north-west monsoon disappears from the East Indian Archipelago, and gives place to the south-east trade-wind, which is known as the east monsoon, just as the north-west wind, which prevails during the southern summer, is called the west monsoon. This is the only north-west monsoon which is found in the southern hemisphere. While in the northern hemisphere the north-east trade-wind blows in the China Sea and in the Indian Ocean, in the East Indian Archipelago the west monsoon prevails; and when here the south-east trade blows as the east monsoon, we find the south-west monsoon in the adjacent seas of the northern hemisphere. Generally the westerly monsoons blow during the summer months of the hemisphere wherein they are found.
704. Thunder and lightning.—"In the Java Sea, during the month of February, the west monsoon blows strong almost continually; in March it blows intermittently, and with hard squalls; but in April the squalls become less frequent and less severe. Now the changing commences; all at once gusts begin to spring np from the east: they are often followed by calms. The clouds which crowd themselves upon the clear sky give warning of the combat in the upper air which the currents there are about to wage with each other. The electricity, driven thereby out of its natural channels, in which, unobserved, it has been performing silently, but with the full consciousness of its power, the mysterious task appointed to it, now displays itself with dazzling majesty; its sheen and its voice fill with astonishment and deep reverence the mind of the sailor—so susceptible, in the presence of storm and darkness, to impressions that inspire feelings both of dread and anxiety, which by pretended occupa-
