February i8, 19 15] 



NATURE 



685 



10,000 square yards. The hills are about 70 ft. high, 

 ind have an area of about 39,000 square feet; these 

 re made in reinforced concrete about 3 in. thick. The 

 low er terraces where the heavier animals are quartered 

 have thicknesses varying- from 5 to 7 in. No two 

 square yards of surface are alike. The entire area 

 was divided into squares of approximately 7 ft. side 

 by radial and concentric lines. Contours along each 

 of these lines were drawn, and these, together with 

 1 plaster model, enabled the scaffolding and centering 

 10 be erected. Timber being out of the question for 

 the centering on account of the irregularity of the 

 surface, a simple and effective substitute was found in 

 wire netting having a fairly small mesh. By mixing 

 the concrete fairly dry, very little escaped through the 

 meshes. The whole is supported on reinforced con- 

 crete columns ; very wide and shallow beams span the 

 columns in both directions, and are embodied in the 

 thickness of the slabs which form the surface of the 

 terraces and hills. The work was completed in 

 thirteen months. 



Messrs. John B.artholomew .and Co., of the Geo- 

 graphical Institute, Edinburgh, have published a new 

 and revised edition of their " Route Chart of the 

 World," which is sold at \s. on paper, and \s. 6d on 



cloth. 



The Proceedings of the third International Con- 

 gress of Tropical Agriculture, held at the Imperial 

 Institute at the end of June last, have been published 

 by Messrs. John Bale, Sons and Danielsson, Ltd., in 

 one volume, at the price of lo-s. net. An article de- 

 scribing the meetings of the congress was published 

 in the issue of Nature for July g, 1914 (vol. xciii., 

 p. 489). The volume has been edited by the honorary 

 secretaries of the congress. It runs to 407 pages, and 

 includes abstracts of the papers supplied by the 

 authors, reports of the discussions, and" the address 

 of the president, Prof. W. R. Dunstan. More than 

 150 papers, coming from authorities in fifty different 

 countries, were presented to the congress, and the 

 principal problems connected with tropical agriculture 

 were dealt with. 



Among the forthcoming books of the Oxford Univer- 

 sity Press are the following : — In Anthropology : — 

 Aboriginal Siberia • a Study in Social Anthropology, 

 M. A. Czaplicka, illustrated; Contributions to the 

 Ethnology of the Salish Tribes, J. A. Teit; Lower 

 L'mpqua Texts, L. J. Frachtenberg. In Biology : — j 

 Heredity and Environment, E. G. Conklin. In Geo- j 

 graphy : — - Historical Geography of South Africa, Sir | 

 C. Lucas, part ii., from 1895 t*^ the Present Day; 

 Geography of Eastern Asia, D. Paton ; The Voyages 

 of the Norsemen to America, W. Hovgaard (Scan- 

 dinavian Monographs, vol. i.). In Medical Science : — 

 The Evolution of Modern Medicine, Sir W. Osier. In 

 Miscellaneous publications : — Scientific Management, 

 C. B. Thompson ; Architectural Acoustics, W. C. 

 Sabine.— The Cambridge University Press announces 

 for early publication the following volumes in the 

 " University of Chicago Science Series " : — The Origin 

 of the Earth, Prof. T. C. Chamberlin ; The Isolation 

 and Measurement of the Electron; Prof. R. A. Milli- 

 NO. 22fiA. VOL. Qa1 



kan; Finite CoUineation Groups, Prof. H. F. Blich- 



feldt. — Henry Holt and Co. {New York) announce : — 

 The Functions of the Nervous System and the Special 

 Senses,^ R. P. .Angier; General Zoolog}', Prof. E. G. 

 Conklin ; Economic Zoology and Entomology, Prof. 

 V. L. Kellogg and R. \V. Doane; Industrial and 

 Commercial Geography for High Schools, Prof. J. R. 

 Smith: College Text-book of Botany, Prof. 1). >. 

 Johnson. 



OUR ASTRONOMICAL COLUMN. 



A New Comet, 1915a (Mellishj.— A telegram from 

 Prof. Stromgren, Copenhagen, received at the Royal 

 Astronomical Society on February 12, announces the 

 discovery- of a small bright comet by Mr, J. E. Mellish, 

 of Madison, Wisconsin, L'.S..\., in the position R.A. 

 i7h., declination 3° N., and moving slowly east. .\ 

 further telegram received on February 16 announces 

 that on February 14 the position was R..A. i7h. 7m.. 

 declination 2° 54' N. The comet is thus in Ophiu- 

 chus, and rises about 2 a.m., so that it should be 

 visible in a small telescope between that hour and 

 daybreak. 



The Zodiacal Light. — ^Those who are in a position 

 to make observations of the zodiacal light will find 

 some very useful information in the noTes on this 

 subject pubhshed in the U.S. Monthly Weather Re- 

 view (September, 1914J, by Mr. Maxwell Hall. The 

 author describes the chief points which should receive 

 the observer's careful attention, and suggests the best 

 seasons for studying the eastern and western branches. 

 Naturally, low latitudes are best suited for the ob- 

 servation; the fact that no instruments are required, 

 but simply a level terrace and wide expanse of sky 

 should multiply the number of those who observe this 

 interesting and beautiful phenomenon. 



ASTROXO.MY AND Mathe.matics. — In an addn^.- — - 

 vice-president and chairman of Section A (.Astronomy 

 and Mathematics) of the American Association for the 

 .Advancement of Science, Dr. Frank Schlesinger took 

 as his subject the object of astronomical and mathe- 

 matical research {Science, Januar}- 22). The address 

 takes the form of pointing out to the astronomer and 

 mathematician the great need of mutual help, and the 

 tendencv of meetings of mathematical and astro- 

 nomical societies to increase the separation between 

 these two sciences. Dr. Schlesinger directs attention 

 to numerous astronomical problems in the solution of 

 which the help of the mathematician is needed, and 

 takes as an example that which concerns spectroscopic 

 binaries, which offers a rich field. 



The Madrid Observatory's Annual for 1915. — The 

 .Annual for 1915 issued by the Madrid Obser\'ator\- 

 under the editorship of Prof. Iniguez, is a volume of 

 703 pages. The first two hundred pages are devoted 

 to tabular statements regarding the ephemerides of the 

 sun and moon, followed by those of planets, satellites, 

 and comets, and facts dealing with eclipses and 

 occultations, together with some numerous useful 

 tables. These are followed by several articles by 

 different authors, among which may be mentioned a 

 long article on time determination, and a preliminary 

 account of the solar eclipse expedition of .August last. 

 A resumi of the observations of the sun made at the 

 Madrid Obser\'ator}- during 1913, including spots, 

 faculae, prominences, etc., is given, concluding with 

 the meteorological observations made during the same 

 year. 



What is Gravitation ?—" It is scarcely too much 

 to say that the nature of gravitation remains as much 



