354 SCIENCE PROGRESS 



T. KuBOTA, " Geodatische Linien auf konvexen Polyederflachen," Sci. Rep. 



Tohoku, 10, 1921, 411-16. 

 K. ZiNDLER, " 0ber konvexe Gebilde," Monatshefte Wien, 32, 1922, 107-38. 



D. KoNiG, " Ober konvexe Korper," Math. Zs., 14, 1922, 208-10. 



T. KuBOTA, " Notes on Closed Convex Curves," Tohoku Math. J., 21, 



1922, 21-5. 

 T. KojiMA, " On the Curvature of the Closed Convex Curves," ibid., 15-20. 

 H. Rademacher, " Uber eine funktionale Ungleichung in der Theorie der 



konvexen Korper," Math. Zs., 13, 1922, 18-27. 



E. Salkowski, " Ober den gemischten Flacheninhalt zweier ebenen Figuren," 



Math. Zs., 14, 1922, 230-5. 

 W. S. Ford, " On Kakeya's IVIinimum Area Problem," Bull. Am. Math. 

 Soc, 28, 1922, 45-53. 



METEOHOLOGY. By E. V. Newnham, B.Sc, Meteorological Office, 

 London. 



Hurricanes and Tropical Revolving Storms, by Mrs. E. V. 

 Newnham, M.Sc. (Geophysical Memoir No. 19, Meteorological 

 Office, Air Ministry). — The storms with which the bulk of this 

 memoir deals have different names in different parts of the 

 world. They are " hurricanes " in the West Indies, " cyclones " 

 in the Bay of Bengal and Arabian Sea, " typhoons " in the 

 China Seas, " baguios " in the Philippines, and" Willy- Willies " 

 in West Australia. They are violent atmospheric whirls 

 round centres of low barometric pressure and have a diameter 

 varying from 100 to 600 miles. The winds circulate round a 

 central " eye " or calm area which averages about 14 miles 

 in diameter, the direction of rotation being counterclockwise 

 in the Northern Hemisphere and clockwise in the Southern 

 Hemisphere. Originating over the ocean in the Doldrums, 

 generally between 8° and 12° north or south of the Equator, 

 the vast majority move westwards at first and then turn 

 polewards, the westward component being gradually reversed. 

 The velocity of the wind is greatest in the region immediately 

 adjoining the central " eye," and may considerably exceed 

 100 miles per hour. When passing over land their energy 

 declines and they gradually die away. Rain falls very heavily 

 in the region of strong winds, but in the central calm the sky 

 is often clear. The revolving storm to which the above descrip- 

 tion applies is quite distinct from the much smaller and more 

 violent " tornadoes " of North America, but less distinct from 

 the " cyclones " or " depressions " of temperate latitudes. 

 The latter are, however, larger and less intense, and seldom 

 have a calm central area with clear skies. The true tropical 

 cyclone, it may be noted, frequently continues its poleward 

 movement into the region of prevailing westerly winds, rapidly 

 losing its special characteristics, until it becomes a normal 

 cyclonic depression of the temperate zone, moving towards 

 the east. 



