STORMS, HURRICANES, AND TYPHOONS. 407 



will pass to the west, but the wind will change from S.E. to 

 S., and so on to the west, with the hands of a ivatch, though 

 it be revolving about the centre against the hands of a icatcli ; 

 still the rule for finding the direction of the centre holds good : 

 Face the wind, and the centre in the northern hemisphere will 

 be to the right ; in the southern, to the left. 



792. Suppose that in the case before us tiie storm is travelling 

 The wind stronger to tlio north at the rate of 20 miles the hour, and 

 cther.^ that the wind is revolving around the centre also 

 at the rate of 20 miles the hour : when the, vortex bears west of 

 the ship, the wind will be south. It is going 20 miles to the 

 north with the body of the storm, and 20 miles around the 

 centre ; total force of the wind, 40 miles an hour on the east side. 

 Now imagine yourself on the other side, that is, that you are in 

 the north-west quadrant, and that the storm is travelling due 

 north as before ; the vortex will pass east of you, when the wind 

 should have changed from N.E. to north, turning against the 

 hands of a watch ; but when the wind is north, it is, in the case 

 supposed, travelling south at the rate of 20 miles an hour around 

 the storm, while the progressive movement of the storm itself is 

 north at the rate of 20 miles an hour. One motion exactly can- 

 cels the other, and there is, therefore, aline of calm and light, or 

 moderate or not so heavy winds on one side of the centre, while 

 on the other side there is a line of maximum violence ; in other 

 words, in every travelling cyclone the wdnd blows harder on one 

 side than tlie other. This is the case in both liemispheres ; and 

 by handling these moving diagrams for illustration, the navigator 

 wall soon become familiar with the various problems for de- 

 termining theoretically the direction of the vortex, the course 

 it is travelling, its distance, etc. Therefore, when it is optional 

 with the navigator to pass the storrn on either side, he 

 should avoid the heavy side. These remarks apply to both 

 hemispheres. 



793. Captain Toynbee asks if it rains more in one quarter of 

 The rainy quadrant a cycloue than another? In cyclones that travel 

 of a cyclone. ^^^^^ J supposo there would be most rain in the 

 after quarter ; with those that have little or no progressive 

 motion, I conjecture that the rainy quarter, if there be one, 

 would depend upon the quarter whence that wind comes that 

 brmgs most rain. The rain in a cyclone is supposed to come 

 from the moisture of that air which has blown its round and oone 



