5 38 THE POPULAR SCIENCE MONTHLY. 



tion aloft sets in, and the precipitation only serves to add " fuel to 

 the flames " of the cyclonic engine. This process widens in geograph- 

 ical area, and, after a few hours have elapsed, the storm may so 

 ^develop as to cover a continent with its portentous canopy of cloud, 

 while simultaneously strewing an ocean with wrecks, and throwing 

 out, in the upper sky, more than a thousand miles in its front, the 

 fine filaments of the premonitory cirrus and cirronus. 



Fig. 1. 



CIRKUS-CIRRONPS CLOUDS. 



In close connection with the size and magnitude of cyclones must 

 be considered the distance over which they pass from their initial 

 point. Much has been said on this part of our subject, and not a few 

 writers have accepted the doctrine of Admiral Fitzroy that they pro- 

 gress over but comparatively short distances. For such a view, how- 

 ever, it is impossible to find, either in the nature or physical office of 

 the cyclone, any support whatever. The storm once engendered, no 

 matter in what part of the world, may be stationary or progressive. 

 There are well-authenticated instances of almost stationary cyclones 

 and almost stationary typhoons, of which latter will be remembered the 

 famous gale of the ship Charles Heddle an Indiaman, carried round 

 and round the storm-centre for five days which progressed not more 

 than ninety miles a day. Indeed, we may, as has been said, regard 

 every wet-monsoon region as a stationary and semi-perennial cyclone. 



