Cyclones and Anticyclones

Abstract

I WILL endeavour to put into a written form the ideas which have occurred to me respecting the law which, as I suppose, connects and governs the atmospheric phenomena which I see referred to in the newspapers as cyclones and anticyclones. I have seen it stated, as the result of observation, that in whatever direction the wind may be blowing at any given time, if you place your back to it the barometer will be found to stand lower upon your left than upon your right. I have also seen it stated that what are termed cyclones are rotatory movements of the air occasioned by the meeting and passing one another of two currents of air moving in opposite, or nearly opposite, directions, and that these cyclones or rotatory storms, though differing much in area, have certain features common to most, if not all, of them; namely, that the direction of their rotation is from right to left, or, in other words, the opposite of the motion of the hands of a watch, and that in their centre is found a considerable diminution of atmospheric pressure. On the other hand, in what is termed an anticyclone, the direction of the rotatory movement is in the opposite direction, that is, from left to right, or in the same direction as the movement of the hands of a watch, while in the central region the barometer is found to be standing high.