562 



NA TURE 



[April 12, 1900 



discrimination. Other things being equal, sulphate of 

 ammonia is more suitable than nitrate of soda for use 

 in the West of England, whereas the order is reversed in 

 the drier climate of the Eastern districts. The behaviour 

 of soluble plant-food under the influence of heavy rain- 

 fall should be considered by farmers in purchasing their 

 supplies of spring manures. The excessive rainfall of 

 the past winter — especially coming, as it did, after a long 

 period of drought— must have very seriously depleted 

 the soil of its natural nitrates, so that increased purchases 

 of active nitrogenous manures for the crops of the current 

 year are clearly indicated. 



Let us hope that the reception given to the present 

 volume will induce the author to proceed, without-delay, 

 to redeem his provisional promise of a work on the cog- 

 nate subject of the chemistry of soil. W. S. 



Electric Wiring, Fittings, Switches and Lamps. By 



W. Perren Maycock, M.LE.E. Pp. xv + 446 ; with 



360 illustrations. (London : Whittaker and Co. 



1899.) 

 Electric Bells and Alarms. By F. E. Powell. Pp. 



"JT ; with 51 illustrations. (London: ]])awbarn and 



Ward, Ltd.) 

 Mr. Perren Maycock, who has already written a num- 

 ber of excellent text-books on electrotechnical subjects, 

 has produced in the present case a book which, while 

 offering no particular attractions to the non-technical 

 reader, undoubtedly serves the purpose for which it is 

 written ; namely, to give a thorough idea of present 

 practice in the electric lighting of buildings. The book 

 is the more welcome since the widespread introduction 

 of 200 and 220 volt lamps during the last three years 

 has rendered all books dealing with electric-light fittings 

 written previous to that time seriously out of date. 

 It is not merely the perfecting of the 200 volt lamp 

 which has rendered this change possible. The design 

 of lamp-sockets, switches and fuses has been of late 

 much improved. The fewness of parts, the simplicity 

 of construction, and the ease and security of wiring 

 of the modern lamp-socket are in striking contrast to 

 the older fittings. These improvements, though appar- 

 ently trivial, are none the less important. 



Another change of the last few years has been the 

 gradual displacement for all but street lighting of the 

 open arc by the enclosed arc lamp, with its greatly 

 lengthened arc and its increased electromotive force and 

 reduced current. Mr. Maycock's passing description of 

 the Nernst lamp reminds one that that most promising 

 novelty has not yet made its debut as a commercial 

 article. 



The illustrations to the text are numerous, and the 

 sectional drawings on the whole very clear. The prac- 

 tice of taking illustrations largely from manufacturers' 

 trade-lists, which is usually to be deplored, is in the 

 present case justified. In no other way could the fittings 

 at present available be properly described. We recom- 

 mend Mr. Maycock's book as the best we have seen on 

 the subject. 



Mr. Powell's unpretentious little book or pamphlet on 

 electric bells and alarms forms No. 3 of the " Model 

 Engineer" series. It furnishes the reader with an attrac- 

 tive and satisfactory account of the various forms of a 

 most useful, if humble, piece of electrical apparatus. 



D. K. M. 



Report of the Marine Biologist for the Year 1898. Cape 

 of Good Hope Department of Agriculture. Pp. v-|- 

 362. (Cape Town : Richards, 1899.) 

 The Cape Government is to be congratulated upon the 

 success which has attended its efforts to investigate the 

 sea-fisheries of the Colony. Dr. Gilchrist, the marine 

 biologist who was appointed to inquire into the best 

 means of developing the fisheries, was undoubtedly well 



NO. 1589, VOL. 61] 



advised in securing, at the very commencement of his 

 undertaking, a properly equipped steam fishing vessel of 

 sufficient size and power to safely keep the sea, and the 

 results recorded in the present report justify, in a man- 

 ner almost beyond what could have been anticipated, 

 the expense which the purchase and up-keep of such a 

 vessel has entailed. It has been clearly shown that the 

 seas around the Cape of Good Hope contain a vast 

 source of unexploited wealth, the development of which 

 would provide a valuable and healthy addition to the 

 food- supply of the people. So far as can be gathered 

 from the report, the only difficulty to be contended with 

 is that of getting the fish to the centres of population in 

 a fresh condition. With a climate such as that of Cape 

 Colony it would seem that the best means of overcoming 

 this difficulty is by the use of refrigerating chambers both 

 on the fishing-vessels themselves and on the trains used 

 for transporting the fish by land. 



The present report does not attempt to deal with 

 the more scientific aspects of fishery investigation, al- 

 though there is evidence that this side of the question is 

 not being altogether neglected. It is of the greatest 

 importance that the newly discovered fishing-grounds 

 should be very thoroughly investigated at the present 

 juncture, before much fishing has taken place upon 

 them, and this investigation should deal, not only with 

 the fish population, but quite as thoroughly with the 

 lower forms of life, which are the food of the fishes. Such 

 an investigation will be invaluable in after years, as it 

 will make it possible to ascertain exactly what influence 

 constant fishing has produced, and many evils which 

 have arisen in the European fisheries may be avoided. 

 It is greatly to be desired that the Government of the 

 Cape of Good Hope will show themselves sufficiently 

 enlightened to realise the immense value of accurate 

 scientific investigations at the present time, and the 

 unique opportunity which they now possess — an oppor- 

 tunitg which will probably never return— of developing 

 their fisheries upon sound and scientific principles, based 

 upon a trustworthy record of facts. E. J. Allen. 



Science Course for Secondary Schools. By G. Robb and 

 J. Mirguet. In Three Parts. I. " Practical Physics," 

 pp. 167; II. "Notions of Physics," pp. 247; 

 III. " Practical Chemistry," pp. 182. (Cairo : National 

 Printing Office, 1898-99.) 

 These three small volumes have been specially com- 

 piled to meet the requirements of the Science Syllabus 

 prescribed by the Ministry of Public Instruction to be 

 used in the Secondary Schools under the management 

 of the Egyptian Government. 



Part i., " Practical Physics," consists of a series of 

 experiments illustrative of the initial phenomena to be 

 observed by the elementary pupil during his first year. 

 The plan adopted is to first describe an experiment, and 

 afterwards enunciate the law to be associated with it. 

 The first five chapters deal with measurements of length, 

 area, volume, force and weight, succeeding chapters being 

 devoted to density, composition of forces, centre of 

 gravity and equilibrium, properties of matter, elementary 

 hydrostatics and theory of gases. The text is sufficiently 

 ample for clearness without being so detailed as to take 

 the place of a text-book. 



Part ii., " Notions of Physics," is in effect a text-book 

 for the assistance of second year pupils in following the 

 series of demonstrations given by the teacher, which 

 constitute the whole of the second year's course. If, as 

 the author's statement appears to indicate, it is a fact 

 that for a complete year the students simply attend a 

 course of experimental lectures without doing any 

 practical work themselves, this would hardly, according 

 to modern views, be consistent with the pupils obtaining 

 the maximum advantage from their instruction. The 

 opening chapters deal with the phenomena connected 



