Also, generally speaking:—
When the glass falls low,
Prepare for a blow;
When it rises high,
Let all your kites fly.[28]
To these short expressions—well known, in practice, to the experienced; a very concise but sure rule may be added, for avoiding the central or strongest part of a hurricane, cyclone, typhoon, tornado, or circling storm.
With your face towards the wind, in North latitude, the centre of the circling, or rotatory storm, will be square to your right. In South latitude, square to your left.
The apparent veering of the wind, and the approach or retreat of the dangerous central circle, depend on your position in the curvilinear whirl or sweep.
Draw a circle;—mark the direction of the rotation or circulation, by an arrow with the head towards the left hand (against the movement of a watch's hands) in North latitude; but towards the right (or with the hands of a watch) if in South latitude. The direction of the wind, and the bearing of the centre, show your position in the meteor, for such it is, though perhaps hundreds of miles in diameter; and the veering of the wind, or the contrary, and its change in strength, will show how the meteor is moving bodily—over an extensive region, revolving horizontally—or inclined at a certain angle to the horizontal plane.
If the observer be stationary, in North latitude, and the centre pass on his polar side, he will experience a change of wind from Southward by the West towards North; but if it pass between him and the Equator, the change will be from Southward by the East towards North; but otherwise in South latitude, as his place in circles sketched will show more clearly than words. The roughest sketch or diagram, indicating the various directions of wind, and the course of the meteor's centre, will show more plainly than descriptions—which must necessarily vary with each case, and are tedious.
Cyclonology, or really meteorology, is simple enough in these great characteristic effects; but their causes must be the philosopher's study, rather than that of the young practical seaman.
Were it not for this reflection, one might endeavour to show how all the great Easterly trade winds—the no less important anti-trades,[29] or nearly constant Westerly winds,—and their complicated eddying offsets, are all (on greater or smaller scales) breadths, or zones of atmosphere, alternating, or circulating, or crossing (superposed or laterally)—between which, at distant intervals, occur those strong eddies, or storms, called hurricanes—typhoons—tornadoes—or cyclones.