March lo, 1898] 



NATURE 



435 



in what units the answer is obtained ; presumably it is in 

 pounds. The one section which is very disappointing 

 is that devoted to gas engines ; only three pages are 

 given to them, and one of these is filled with a 

 useless description of the two original types — the 

 Lenoir and Otto and Langen, both of course interest- 

 ing in an historical account of the origin of the gas 

 engine, but not of the slightest value or claim to notice 

 in a pocket-book : in future editions it is to be hoped 

 more attention will be given to this section, and that the 

 page mentioned will be cut out. The author would have 

 done well to make use of the recent determination of the 

 mechanical equivalent of heat ; most engineers are now 

 adopting 778 as the figure. On p. 93 occurs an awkward 

 misprint in the formula for mean pressure of steam ; the 

 letter in the denominator should be R, and not P, as 

 printed. The rules given for the cooling surface of surface 

 condensers, on p. 113, must apply only to single-cylinder 

 eVigines ; at any rate, they give areas greater than 

 usually adopted in the best modern practice for triple 

 compound plants. The sections devoted to pipes and 

 gearing are admirable, and there are many most useful 

 tables ; the last fifty or sixty pages contain a valuable 

 collection of tables of weights of various sections of iron 

 and steel, areas of circles, cubes, square roots, &c. We 

 have pointed out a few blemishes, but the book as a 

 whole is very free from slips or errors, and will be, no 

 doubt, of service to many engineers, draughtsmen, and 

 works-managers. H. B. 



Handbooks of Practical Science. No.- I. Mensuration^ 

 Hydrostatics and Heat. Pp. 53. No II. Chemical 

 Experiments. Pp. 58. By G. H. Wyatt, B.Sc, 

 A.R.C.Sc. (London: Rivingtons, 1897, 1898.) 

 Science Handbooks for Laboratory and Class Room : 

 Elementary Physics, Practical and Theoretical. First 

 Year's Course. By John G. Kerr, M.A. Pp. 140. 

 (London : Blackie and Son, 1898.) 

 Quantitative Practical Chemistry. Part I. Elementary 

 Stage. Pp. 55. Part II. Advanced Stage. Pp. 31. 

 By A. H. Mitchell, B.Sc. (Reading : National Pub- 

 lishing Association, Ltd., 1897.) 

 A NUMBER of simple and instructive experiments are 

 described by Mr. Wyatt in the practical handbooks 

 referred to above. Following sound educational prin- 

 ciples the student is told what to do, but so far as it is 

 practicable he is left to find out for himself the con- 

 clusions to be drawn from the experiments. In this respect 

 the books are constructed upon the lines of others which 

 are already in use in schools where elementary science is 

 taught. A few practical exercises are given on the 

 principles brought out by the experiments ; but the 

 teacher will find it necessary to considerably increase the 

 number of these, if he wishes his pupils to remember 

 what they have done. In his shorthand manuals Sir Isaac 

 Pitman used to advise the students who wished to become 

 proficient in the art of phonography to " Practice, Practice, 

 Practice," and the same advice applies to instruction in 

 elementary science. Not one or two, but twenty or thirty 

 experiments are, for instance, necessary before young 

 students can thoroughly understand the significance 

 of the principle of Archimedes. The difficulty in the way 

 of carrying out so much experimental work is one of 

 time, and if a large amount of work has to be accom- 

 plished in a short time, the depth of knowledge is thinner 

 in proportion to the area covered. 



In the first of Mr. Wyatt's handbooks, the usual 

 elementary exercise* in mensuration, hydrostatics and 

 heat are given ; while the second contains simple experi- 

 ments on general chemical processes, air, combustion, 

 carbon, various common substances, such as salt, lime, 

 &c., acids, alkalis, hydrogen, water, chalk, and important 

 gases. Too much ground is covered in the latter volume 

 for the work to give satisfactory results, but taken as a 



NO. 1480, VOL. 57] 



whole the handbook will be found very serviceable in 

 teaching the rudiments of science. 



Mr. Kerr's book on elementary practical physics 

 has much to commend it, and deserves to be widely 

 adopted by pupils commencing the study of physical 

 science. The book contains about a schooly ear's work 

 of three or four hours per week. In the first half a number 

 of experiments to be performed by the pupils individually 

 are described, and in the second half the chapters are 

 more of a descriptive nature, so that they provide material 

 for the pupil to study and wherewith the teacher may 

 exercise him. The principles of measurement, and simple 

 laws of mechanics, form the subjects of the experiments, 

 and the author has introduced many ingenious methods 

 into his work. The pupil who carries out the experi- 

 ments will be given knowledge which he is not likely to 

 forget. Moreover, as the experiments are mostly quan- 

 titative, they oflfer a valuable course of training for the 

 mind. 



Ability to perform simple quantitative experiments is 

 now required by the Department of Science and Art 

 from students of both the elementary and advanced 

 stages of practical chemistry. The object of Mr. 

 Mitchell's sleijder volumes is to supplement existing text- 

 books by exercises bearing upon the new requirements. 

 Part I. contains experiments on measurement of length, 

 volume, specific gravity and common chemical changes, 

 and Part II. is concerned with the experiments in volu- 

 metric analysis so far as they are required of students in 

 the advanced stage. 



Researches on Tuberculosis. The Weber-Parkes Prize 

 Essay, 1897. By Arthur Ransome, M.A., M.D. 

 (Cantab), F.R.S., Consulting Physician to the Man- 

 chester Hospital for Consumption, &c. 

 The book before us is the reprint of an essay written in 

 accordance with certain specific regulations framed by 

 the Royal College of Physicians. This diminishes to 

 some extent the general value of the book, as it almost 

 confines its contents to the individual experience and 

 results of the author. These latter are, however, ver)' 

 extensive, and almost all ground of interest in this 

 subject is to some extent covered. A lengthy chapter 

 is devoted to the natural history of the tubercle bacillus, 

 another to preventive and prophylactic measures ; 

 channels and sources of infection are also fully con- 

 sidered. The book concludes with a chapter upon the 

 direct treatment of phthisis. In this connection it may be 

 mentioned that the author seems to have obtained ver)- 

 satisfactory' results from the inhalation of ozone. We 

 are pleased that the Royal College of Physicians gave 

 its consent to the publication of this essay, as the book 

 will no doubt be of considerable interest to those engaged 

 in researches upon this subject. F. W. T. 



" The Electrician " Electrical Trades' Directory and 

 Handbook for 1898. (Sixteenth Year). Pp. 918 -|- 

 cxliii. (London : The Electrician Printing and Pub- 

 lishing Co., Ltd., 1898.) 

 The Universal Electrical Directory (/. A. Berlfs). 

 Pp. 1 182. (London: H. Alabaster, Gatehouse, and 

 Co., 1898.) 

 These two ponderous volumes give evidence of the 

 remarkable growth of the electrical and allied industries 

 during the paat few years. Two large sheets, folded in 

 the first of the volumes at the head of this notice, give 

 particulars of the present electric supply works of the 

 United Kingdom, and the electric railways and tram- 

 ways. Ver}' few of the supply stations were in existence 

 at the beginning of 1890, and if the progress is as great 

 in the next eight years as it has been in the past eight 

 years, few districts w ill be without electricity for light, 

 power and traction purposes. The biographical division 

 of the Directory is of more than professional interest, 

 as it contains short sketches of the careers of many 



