, i6o 



NATURE 



[April 19, 1917 



divisions. — S. Hatai : The composition of tlje Medusa, 

 Cassiopea xamachana, and the changes in- it after 

 starvation. — H. Shapley : Studies of the magnitudes in 

 star clusters, iv. On the colour of stars in the galactic 

 clouds surrounding Messier ii. The frequency-curve 

 for colours shows great diversity of colour index and 

 general resemblance to the curve for the brighter stars 

 in the neighbourhood of the sun. A striking pro- 

 gression of colour with decreasing brightness is shown. 

 — F. H. Scares : The colour of the standard jjolar stars 

 determined by the method of exposure-ratios. The 

 colours of the polar standards, brighter than the 13th 

 magnitude, have been determined to about the same 

 precision as was reached in the investigation of the 

 magnitude scale, with an expenditure of time and 

 labour perhaps a tenth of that in an earlier investiga- 

 tion. ^C. Keyes : Terracing of bajada belts. The fea- 

 ture of desert bajada-terracing, when explained upon 

 a strictly aqueous basis, cannot but lead to complete 

 misinterpretation. It is far more largely the result 

 of wind-action. — C. D. Perrine : Relation of the apex 

 of solar motion to proper motion, and on the cause 

 of the differences of it«; position from radial velocities 

 and proper motions. — Brig.-Gen. H. L. Abbot : Hydro- 

 logy of the Isthmus of Panama. Extensive tables 

 for rainfall, outflow, evaporation, etc., are given and 

 discussed. — C. P. Olivier : The meteor system of Pons- 

 Winnecke's comet. The elements of the meteor's orbit 

 are determined from more than 1000 observations. — 

 T. W. Richards and H. S. Davis: Improvements in 

 calorimetric combustion, and the heat of combustion. 

 The improvements are : means of effectively closing 

 the bomb with less risk to the lining and cover; means 

 of burning volatile liquids without loss ; a method of 

 automatically controlling the temperature of the en- 

 vironment; means of evaluating the incompleteness 

 of combustion. The heat of combustion of toluene is 

 determined as 10-155 calories (18°) per gram. — R. C._ 

 Tolman and T. Dale Stewart : The mass of the electric 

 carrier in copper, silver, and aluminium. A continua- 

 tion of experiments on cuirents produced bv accelera- 

 tion in metals.— E. B. Rosa and G. W. Vinal : The 

 silver voltameter as an International standard for the 

 measurement of electric current. .\ summary of eight 

 years' experimental work which has shown' how the 

 voltameter can be used as a trustworthy current 

 standard and as a means of checkinr^ the constancy 

 of the value of the Weston normal cell. 



BOOKS RECEIVED. 



. Guide to Materials for American Historv in Russian 

 Archives. By Prof. F. A. Golder. Pp. 1S5. (Wash- 

 ington : Carnegie Institution.) i dollar. 



Theorie de la Contre-Evolutlon ou Deg^n^rescence 

 par I'H^r^dlt^ Pathologlque. By Dr. R. Larger. 

 Pp. xiv-f4o5. (Paris: F. Alcan.) 7 francs. 



Dairy Farming. By Prof. C. H. Eckles and Prof. 

 G. F. Warren. Pp. xv-f-^og. (New York : The Mac- 

 mlllan Co.; London: Macmillan and Co., Ltd.) 

 55. net. 



Air Power : Naval, Military, Commercial. Bv C. 

 Grahame-White and H. Harper. Pp. 262 + 20 Illus- 

 trations. (London : Chapman and Hall, Ltd.) 7s. 6d. 

 net. 



DIARY OF SOCIETIES. 



THURSDAY. April 19. 



Royal Institution, at 3.— Industrial Finance after the War; The 

 Character of the Indnstrial Struggle of To-Hay - Prof. H. S. Foxwell. 



Mathematical Society, at 5.30.— A Liquid Gyrostat: Prof._W. Burn- 

 ^idei — The Integral Formula for Generalised Legendre Functions: 

 G._N. Watson.— A Substitution Permutable with the Transposed Substi- 

 tution : Prof. H. Hilton. 



LiNNEAN Society, at 5;— The HeteranTiuihs of the British Coal Measures: 

 Dr. D. H. Sc^tt. — Hypophysis ^nd Premandibular Cavities; a Sug- 

 eest'on : E. S. Goodrich.— Wooden Scratching Tools made by an African 

 Parrot: MissN. Layard. 



Institution of Mining and Mei allurgv, at 5. jo.— Annual General 

 Meeting. — Slope Measurement at Messina: W. Whyte. — Platinum in 

 • Spain : F. Gillman. 



Chemical Society, at 8. — The Hydration of Ions and Metal Overvoltage : 

 E. Newbery. — The Pungent Principles of Ginger. Part i. A_ New 

 Ketone, Zirigeribone, occurring in Ginger : H. Nomura. — Velocity of 

 Decomposition and the Dissociation Constant of Nitrous Acid: P. C. 

 Kay, .M. L. Dey, and J. C. Ghosh. — The 'Alkaloids of Ipecacuanha. 

 Part ii : F. L. Pyman. — Studies in Catalysis. Part vi. The Mutual 

 Influence of Two Reactions proceeding in the same Medium : R. O. 

 GrifTith, k. Lamble, and W. C. McC. Lewis.— Studies in Catalysis. 

 Part vii. Heat of Reaction, Equilibrium Constant, and Allied Quantities 

 from the Point of View of the Kadiation Hypothesis : W. C. MtC. Lewis. 

 — Note on the Isolation of Methylnonylketone from Palm Kernel Oil : 

 A. H. Salway.— Metallic Derivatives of Alkaloids: J. N. Rakshit. 



Royal Society op Arts, at 4.30. — The Industrial and Economic Develop- 

 .Tient of Indian Forest Products: R. S. Pearson. 



FRIDAY, April 20. 

 RoVAL Institu-tion, at 5.30. — The Future of Wheat-growing in England : 



Prof. R. H. Biffen. 

 Institution of Mechanical Engineers, at 6.— Presidential Address : M. 

 Longridge. 



SATURDAY, Plt^ii. ^i. 

 Royal Institution, at 3.— Principles of Aerial Navigation : Prof. G. H. 

 Bryan. 



MONDA Y, Ai-RiL 23. 

 Aristotelian Society, at 8. — Symposium : Ethical Principles of Social 

 Reconstruction : Principal L. P. Jacks, G. Bernard Shaw, C. Delisle 

 Burns, and Miss H. D. Oakeley. 



TUESDAY, April 24. 

 Royal Institution, at 3. — Russian Development— The Rise of Moscow : 

 Prof. C. R. Beazley. 



WEDNESDA Y, April 25. . 

 Royal Society of Arts, at 4.30.— Flour and Bread : Sir Francis Fox. 



THURSDAY, April 26. 

 . Royal Institution, at 3. — Industrial Finance after the War : Prof. H. S. 

 Foxwell. 

 Institution of Electrical Engineers, at 6. — High-tension Overhead 

 Transmission Lines : G. V. 'I'wiss. 



FRIDAY, April 27. 

 Royal Institution, at 5.30. — The Organs ot Hearing in relation to the 

 War : Dr. Dundas Grant. 



SATURDAY, April 2S. 

 Royal Imstitution, at 3. — Principles of Aerial Navigation : Prof. G. H. 

 Bryan. 



CONTENTS. PAGE 



Education and Research. By H. G. Wells .... 141 



The World Crisis and After 142 



Scientific Observation and Reasoning. By H. R. M. 142 



Our Bookshelf . . . . I43 



Letters to the Editor: — 



Adjustable Clock-dials.— Dr. P. E. Shaw .... I44 



Aeroplanes and Propellers. {Illustrated.') .... 145 

 Researches on Cerebrd-spinal Fever. [Illustrated.) 



By Prof. R. t. Hewlett I47 



Notes 148 



Our Astronomical Column :— 



The Planet Mercury • • • • ^52 



Comet 1917^ (Mellish) ! ... 152 



Laboratory Work in Astrophysics 152 



Parallax of a Planetary Nebula 153 



The Recent Cold Weather. By Chas. Harding . 153 

 Memorial to Sir William and Lady Huggins. 



Address by Sir J. J. Thomson, CM., P.R.S. . . 153 



The Development of Vegetation. By A. G. T. . . 154 



The Zoology of the "Terra Nova" Expedition . 155 



Educational Reform 156 



University and Educational Intelligence . . . 158 



Societies and Academies 158 



Books Received 160 



Diary of Societies .... 160 



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Advertisements and business letters to be addressed to the 

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Editorial Communications to the Editor. 

 Telegraphic Address : Phusis, London. 

 Telephone Nur>}bfir : Gerrard 8830. 



NO. 2477, VOL. 99] 



