In some localities this blows during great part of the night. But the period of its commencement varies in different places, and the intervals of calm between both land and sea-breezes are often of uncertain duration. The land and sea-breezes repeat, on a scale of diurnal variation, the phenomena shown by the monsoons on a scale of yearly change. They show how readily the atmosphere yields to the slightest pressure, and how powerful an influence on the laws of climate, and, with them, on the condition of mankind, is exercised by every change, of temperature, or otherwise, to which it is subject. Similar winds--alternating from opposite quarters of the heavens--are experienced in inland districts, as on the banks of the Tapajos River, in South America. The rotary storms which occur, at uncertain intervals, in particular latitudes, are to be included among the exceptional phenomena of atmospheric change. They prevail, however, over larger areas than was formerly supposed, and perhaps belong to a general system of atmospheric movements in which electric and magnetic influences fill an important place. The hurricanes of the West Indies, the tornadoes and cyclones of the Indian Ocean, and the typhoons of the China Sea, are winds of this description. Within the Southern Hemisphere, the direction of the rotating circle is always found to correspond to the movement of the hands of a watch (_i. e._, from west to north, east, and south): to the north of the equator, the circle of wind follows an opposite direction (or west to south, east, and north). By a knowledge of this law, combined with careful observation of the track usually taken by such storms, mariners are enabled to avoid some of the dangers incident to their occurrence. The destruction which they occasion, however, within maritime tracts exposed to their influence, as well as upon the high seas, is at times fearfully great. Waterspouts are another form in which the rotary movements of the air are manifested. In the case of these phenomena, a taper column of cloud, descending from above, is joined by a spiral column of water which winds upward from the agitated surface of the sea, the two together forming, by their union, a continuous column which moves over the sea. Waterspouts seldom last longer than half an hour. They are more frequent near the coast than on the high seas, and more commonly seen in warm climates. SQUALLS, WHIRLWINDS, AND TORNADOES --SIR RALPH ABERCROMBY