554 



NATURE 



[January 14, 19 15 



to appreciation of scientific method and scientific 

 accuracy. Domestic work might be taught as an art 

 or craft, and more things might be taught in the 

 home — by which was not meant an increase in " home 

 lessons." Girls could be taught to express themselves 

 clearly through science lessons. The address was 

 practical, and will no doubt be helpful to the science 

 mistresses who heard it. It is a matter for great 

 regret that no other paper on science teaching in 

 schools (above the stage of nature-study) appeared at 

 the conferences during Education Week, 19 15. The 

 presidential address delivered by Sir George Greenhill 

 before the Mathematical Association upon the subject 

 of mathematics in artillery science, did, however, deal 

 largely with the unsatisfactory position which science 

 occupies in the training of artillery officers. 



SOCIETIES AND ACADEMIES. 

 London. 

 ■ Physical Society, December 18, 1914. — Dr. A. Russell, 

 vice-president, in the chair. — H. R. Nettleton : A 

 vacuum guard-ring and its application to the deter- 

 mination of the thermal conductivity of mercury. A 

 specially constructed vacuum vessel heated at the top 

 by steam and cooled at the bottom by flowing water, 

 is used to find the thermal conductivity of mercury. 

 The vacuum acts as a guard-ring, which is at the 

 same time not open to the well-known objection of 

 communicating to the calorimeter a quantity of heat 

 difficult to estimate. So efficient is the vacuum that 

 the temperature gradient, as measured by a single 

 thermo-junction carried by a cathetometer, is probably 

 not in error to the extent of i part in 500. The mean 

 value obtained for the thermal conductivity of mercury 

 in a set of twenty-four experiments is 0-01960 c.g.s. 

 units over the range 35° C. to 45° C. The remarkable 

 linear nature of the temperature gradient obtained 

 within the vessel, the cross-section of which was very 

 uniform over the larger range of temperature, 35° C. 

 to 65° C, would indicate at least that there is no 

 diminution of thermal conductivity with rise of tem- 

 perature. 



BOOKS RECEIVED. 



A Text-Book of Practical Assaying. By Prof. J. 

 Park. Revised and enlarged edition. Pp. xii + 342. 

 (London : C. Griffin and Co., Ltd.) 75. 6rf. net. 



Practical Field Botany. By A. R. Horwood. Pp. 

 XV+ 193. (London: C. Griffin and Co., Ltd.) 5s. 

 net. 



A First Book of Commercial Geography. By T. 

 Alford Smith. Pp. viii4-i5i. (London: Macmillan 

 and Co., Ltd.) is. 6a!. 



Calculus Made Easy. By F. R. S. Second edition. 

 Pp. xi + 265. (London : Macmillan and Co., Ltd.) 

 2s. net. 



What Do We Mean by Education? By Prof. J. 

 Welton. Pp. xii4-257. (London : Macmillan and Co., 

 Ltd.) 5s. net. 



Fundamental Sources of Efficiencv. Bv Dr. F. 

 Durell. Pp. 308. (Philadelphia and London : J. B. 

 Lippincott Co.) 105. 6d. net. 



Logic : Deductive and Inductive. By C. Read. 

 Fourth edition. Pp. xvi + 417. (London : A. Moring, 

 Ltd.) 65. 



Directions for a Practical Course in Chemical 

 Physiology. By Dr. W. Cramer. Second edition. 

 Pp. viii4-io2. (London: Longmans and Co.) 3s. 

 net. 



DIARY OF SOCIETIES. 



THURSDAY. January 14. 

 Institution OK Electrical Engineers at 8. — The Shape of the Pressure 

 Wave in Electrical Machinery: Dr. S. P. Smith and R. S. H. Boulding. 

 Mathematical Society, at 5.30. 



MONDAY, January i8. 

 Royal Society ok Arts, at 8.— Oils, their Production and Manufacture : 



Dr. F. Mollwo Perkin. 

 Victoria Institute, at 4.30. — Modernism and Traditional Christianity: 



Rev. Canon E. M'^Clure. 



TUESDAY, January 19. 

 Royal Institution, at 3. — Muscle in the Service of Nerve : Prof. C. S. 



Sherrington. 

 Royal Statistical Society, at 5. 

 Illuminating Engineering Society at 8. — Discussion : Some Points in 



Connection with the Scientific Development and Practical Applications of 



Searchlights. 



WEDNESDAY. January 20. 

 Royal Society ok Arts, at 8. — The Textile Industries of Great Britain 



and Germany: J. A. Hunter. 

 Royal Meteorological Society, at 7.30. — Annual General Meeting. 



Followed by an Account of the Proposed Climatological Atlas of the 



British Isles. 

 Royal Microscopical Society, at 8.— Notes on the History of the 



Microscope : Dr. C. Ginger. 

 Entomological Society, at 8. — Annual Meeting. 

 Geological Society, at 8. — The Geology of the District around 



Machynlleth and the Llyfnant Valley: O. T. Jones and W.J. Pugh. — 



The Geology of the District between Abereiddy and Abercastle (Pem. 



brokeshire): A. H. Cox. 



THURSDAY. January 21. 

 Royal Society, at 4.30. — PtobabU Papers: Atmospheric Electricity 



Potential Giadient at Kew Observatory, 1898-1912 : Dr. C. Chree. — 



Electromagnetic Waves in a Perfectly Conducting Tube : L. Silberstein. 



— An Electrically-heated Full Radiator : H. B. Keene. — T he Trans- 

 mission of Electric Waves over the Surfaces of the Earth : Prof. A. E. H. 



Love. 

 Royal Institution, at 3. — Modern Theories and Methods in Medicine : 



H. G. Plimmer. 

 Royal Society of Arts, at 4.30.— Nepal : H. J. Elwes. 

 Linnean Society, at 5. — Report on the Fishes Collected by Mr. Cyril 



Crossland in the Sudan : Miss Ruth C. Bamber. — Narrative of his 



Recent Visit to the Houtman Abrolhos Archipelago, West Australia : 



Prof. W. J. Dakin. 

 Institution ok Mining and Metallurgy, at 8. 



FRIDAY, January 22. 

 Royal Institution, at 9. — Problems of Hydrogen and the Rare Gases : 



Sir J. Dewar. 

 Institution ok Mechanical Engineers, at 8. 

 Physical Society, at 5. — Practical Harmonic Analysis: Dr. A. Russell. 



— Measuring the Focal Length of a Photographic Lens : T. Smith. 

 SATURDAY. January 23, 

 Royal Institution, at 3. — Aerial Navigation — Scientific Principles : Dr. 



R. T. Glazebrook. 



CONTENTS. PAGE 



The War 527 



Lord Avebury: Banker and Naturalist 528 



Arboriculture and Forestry. By W. Dallimore . . 529 



First Principles of Mathematics. By G. B. M. . . 530' 



Egyptian Folklore. By L. W. K 531 



Our Bookshelf 532 



Letters to the Editor : — 



Experiments on Hay Infusions. — Hugh Richardson 533 



The Ascending Spiral. {^Illustrated.) 533 



Iceberg Observations. By R. N. R. B 535 



Lieut.-Col. D. D. Cunningham, F.R.S 536 



Sir Owen Roberts 537 



Notes . 538 



Our Astronomical Column :— 



Fireballs in January 543 



The Capture Theory of Satellites 543 



Observations of the Moon 543 



Companion to " The Observatory " for 1915 . . . . 543 



The Meteor-fall of Ensisheim (1492) 543 



Chemical Tests and Standards 544 



War and the Race 544 



Standardisation of Electrotechnical Symbols . . . 544 

 German Methods in Commerce. By Sir William 



Ramsay, K.C.B., F.R.S 546 



State Aid for Science. By C. A. Buckmaster ... 547 



University and Educational Intelligence . . 553 



Societies and Academies 554 



Books Received 554 



Diary of Societies 554 



Editorial and Publishing Offices : 



MACMILLAN & CO., Ltd., 



ST. MARTIN'S STREET, LONDON. W.C. 



Advertisements and business letters to be addressed to the 



Publishers. 



Editorial Communications to the Editor. 



NO. 2359, VOL. 94] 



Telegraphic Address: Phusis, London. 

 Telephone Number : Gerrard 8830. 



