536 



NATURE 



[August 24, 19 16 



to put the war in its proper lipht. On the other 

 hand, though it was known that Germany had long 

 maintained a regular organisation of propagandist 

 schools throughout the world, it was not until July, 

 19 15, that steps were taken by the Government of 

 India to intern or repatriate the enemy aliens in 

 India who were engaged in school work, when such 

 schools were handed over to other agencies. 



SOCIETIES AND ACADEMIES. 

 Paris. 

 Academy of Sciences, August 7. — M. Paul Appell in the 

 chair. C. Richet : The monthly variation of natality. 

 For a period of fiifty-seven years the maximum 

 number of births is in February or March. For the 

 years 1906-10 the maximum in these two months 

 is shown in all countries in the Northern Hemisphere, 

 and figures for eleven countries are cited. In the 

 Southern Hemisphere the monthly maximum is in 

 August-October, or a period six months from the maxi- 

 mum in the Northern Hemisphere. The maxima are 

 in the same months both for legitimate and illegiti- 

 mate births, for rural and urban populations, for the 

 poor and rich ; but a relation can be traced between 

 the latitude and the date of the monthly maximum. — 

 C. Camichel : Hammering in water mains : the exam- 

 ination of the state of a main. P. Choffat : The 

 volcanic intrusive rocks of the region situated to the 

 north of the Tagus. — E. Belot : Experimental vol- 

 canoes and the laws of volcanic phenomena. The ex- 

 perimental arrangement described in an earlier com- 

 munication can be modified by the introduction of a 

 layer impermeable to water and steam (slate) above the 

 source of heat. — R. Soueges : The first divisions of the 

 egg, and the origin of the hypophysis in Capsella 

 bursa-pastoris. 



BOOKS RECEIVED. 



Theorie Generale des Nombres : Definitions fonda- 

 mentales. By E. Dumont. Pp. 92. (Paris : 

 Gauthier-Villars et Cie.) 2 francs. 

 . Petit Atlas Celeste. By G. Bigourdan. Pp. 57. 

 (Paris : Gauthier-Villars et Cie.) 2 francs 75 centimes. 



Le Climat de la France : Temperature, Pression, 

 Vents. By G. Bigourdan. Pp. 135. (Paris : 

 Gauthier-Villars et Cie.) 4 francs. 



Mitteilungen der Naturforschenden Gesellschaft in 

 Bern. 1913. Pp. xxxv + 266. 1914- Pp- xxv + 324. 

 1915. Pp. 1 + 315. (Bern: K. J. Wyss.) 



Centenaire de la Societe Helvetique des Sciences 

 Naturelles. Band 1. Pp. vi + 316. (Basel: Georg 

 and Co.) 



Neue Denkschriften der Schweizerischen Natur- 

 forschenden Gesellschaft. Band li. (Basel : Georg 

 and Co.) 



.\ctes de la Societe Helvetique des Sciences Natur- 

 elles, 97me Session. 2 Pts. (.Aarau : H. R. Sauer- 

 lander et Cie.) 



Verhandlungen der Schweizerischen Naturforschen- 

 den Gesellschaft, 1914. 2 Pts. (.\arau : H. R. Sauer- 

 lander et Cie.) 



The Sea-Trout. By H. Lamond. Pp. xi + 219. 

 (London : Sherratt and Hughes.) 21s. net. 



Observations made at the Royal Magnetical and 

 Meteorological Observatory at Batavia. Vol. xxxv. 

 (1912.) Pp. xxvi4-96. Observations made at Second- 

 ary Stations in Netherlands East-India. Vol. iii. 



NO. 2443, VOL. 97] 



(1913.) Pp. ix+119. (Batavia: Government Printing; 

 Office.) 



Results of Registering-Balloon Ascents at Batavip. 

 By Dr. \V. van Bemmclen. Pp. lvii+109. (Batavia: 

 Javasche Bockhandel en Drukkerij.) 



Regenwaarnemingen in Nederlandsch-lndle. . Zes 

 en Dertigste Jaargang, 1914. Deel ii. Uitkomsten. 

 Pp. ix + 230. (Batavia: Landsdruckkerij.) 



Oeeanographische Waarnemingcn in den Indischen 

 Oceaan, Sept., Oct., Nov. (1856-1914). Tabellen : 

 Observations Oceanographiqucs et M^tterologiques 

 dans rOcean Indien. Pp. xi + 240; Kaarten 25, 

 (Utrecht : Versluys and Scherjon.) Text and atlas, 

 6.50 florins. 



CONTENTS. PAGE 



Coal-tar and Ammonia. By Sir T. E. Thorpe, C.B., 



F.R.S 517 



Materials of Construction 5^8 



Sound Analysis. By E. H, B 5^9 



Our Bookshelf 5'9 



Letters to the Editor:— 



The Formation of Dust-ripples.— H. U. G. (C.F.). 520 

 A Sunset Phenomenon on July 22.— Capt. C. J. P. 



Cave 520 



The Utilisation of Waste Heat for Agriculture.- C. 



TurnbuU • 520 



A Peculiar Thunderclap.— H. O. F 520 



Engineering Education and Research in Relation 

 to the Organisation of British Engineering In- 

 dustry, ByJ. C. M. G 520 



The Optical Industry in France 522 



Arctic Oceanography 523 



Notes 523 



Our Astronomical Column :— 



The Solar Physics Observatory 528 



Relative Luminosities of Sun and Stars 528 



The Thermopile in Photographic Photometry . . . 528 



Recent Indian Museum Publications 528 



Recent Economic Entomology. By G. H. C. . . . 529 



Chilian Meteorology. By R. C. M 530 



The Movements of the Earth's Pole. ( IVM Dm- 



oraws.) By Col. E. H. Hills, C.M.G., F.R.S. . . 530 



University and Educational Intelligence 535 



Societies and Academies 53^ 



Books Received 53^ 



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