294 ^^^ POPULAR SCIENCE MONTHLY. 



complex jiarts act interdependently — as the various parts of a steam- 

 engine — yet all constituting one grand mechanism. Nature's forces 

 respect no national frontiers ; and, if their mighty play is to be 

 watched by science, its observational corps must be expanded to 

 cover every accessible part of the globe. This will be made more 

 apparent if we consider the intensities and movements of cyclones. 

 The storms generated over the sea often jDush with resistless energy 

 against the loftiest mountain-walls, and, surmounting their acclivities, 

 press on as if they had felt no retardation, to sweep across an entire con- 

 tinent, and then, untired, to take a fresh start on a long ocean-voyage. 

 In a rigid examination of the Signal-Service data for a period of twen- 

 ty-six months, twenty-eight storm-centers, it was found by Professor 

 Loomis, traveled eastward across the Rocky Mountains, and reached 

 the Mississipi^i Valley in unimpaired vigor, having scaled that impos- 

 ing barrier, 10,000 feet high, as easily as the steamship on its rapid 

 course overrides a wave. In discussing the two cyclones which visited 

 the Bay of Bengal in October, 1876, Mr. Elliott, Meteorological 

 Reporter to the Government of Bengal, incidentally gives us some 

 idea of the cyclopean forces which are developed by such storms. 

 The average "daily evaporation," registered by the Bengal instru- 

 ments, in October, is " '2 inches." * The amount of heat absorbed by 

 the conversion of this amount of water daily over so large an area as 

 the Bay of Bengal is enormous. " Roughly estimated," says Mr. El- 

 liott, *' it is equal to the continuous working power of 800,000 steam- 

 engines of 1,000 horse-power." A simple calculation will show that it 



/ , 





l/ifimi/m/il/iii/ii iiniiiiii/i i ' ^ ^ ^ / //'////////////////////////////////////////////// 



Vertical Section op the Heakt of a Ctclone. (Arrows show direction of wind and the 

 ascending current in storm-center; the dark-shade, nimbus, or rain-cloud.) 



suffices to raise aloft over 45,000 cubic feet of water in twenty-four 

 hours from every square mile of the bosom of the bay, and transport 

 it to the clouds which overhang it. When we extend the calculation 

 from a single square mile to the area of this whole Indian gulf, the 



* "Report of the Vizagapatam and Buckergunge Cyclones of October, 1876," by J. 

 Elliott, p. 182. 



