THE INTERN'ATIONAL WEATHER-SERVICE. 



295 



mind is lost in the effort to conceive the force which, in a clay's 

 time, can lift 50,000,000 tons ! Yet, it would be easy to show that 

 such figures, fabulous as they seem, do not adequately represent the 

 cyclonic forces of a single storm. " The usual size of the cyclones in 

 the Bay of Bengal," according to Piddington, "is from 300 to 350 

 miles ; but," as he adds, "it would appear that they sometimes much 

 exceed that extent " ; and others give the average diameter as still 

 greater than 350 miles. Now, in the passage of a cyclone over such a 

 sheet of water, the vapor which has been slowly generated over its sur- 

 face for many days is rapidly condensed and reconverted into water, 

 and falls in the shape of torrential rains — as Dampier declared, " faster 



North 



KG' 



South 



Horizontal Movements op Air around Center of Cyclone in Northern Hemisphere.— 

 (Lar^e arrow shows path of storm ; smaller arrows, the winds taking a more radial direction, 

 and increasing in velocity, as they near the ceuter.) 



than he could drink it." On the coasts of India, twenty inches have 

 been known to fall in a single night ; in the Bengal storm just men- 

 tioned, 15-2 inches fell in eighteen hours. Assuming that the mean 



