June 14, 1906_ Wirtz (Dr.), Comet 1906b, 494, 544 Wislicenus (Prof. Walter F.), Death of, 33; Obituary Witkowski (Prof. A. W.), the Thermal Dilatation of Com- Wolf (Bertram), a New Oxide of Carbon, 452 Wolf (Prof.), Nova Aquila No. 2, 87; Comet 1905b, 160; Wood (Alex.), Diurnal Periodicity of Ionisation of Gases, Wood (Dr. Ethel M. R.), the Tarannon Series of Tarannon, 502 Woodhead (Prof. Sims), Leprosy in South Africa, 139 Woodman (Prof. J. E.), Geology of the Moose River Gold Woods (Frederick Shenstone), the Boston Colloquium, Woodward (Dr. A. S.), Myriacanthus paradoxus from the Worms the Isolation of the Infecting Organism (" Zoo- Wright (H.), Green Manures, 134; Foliar Periodicity in Wright (Lewis), Death of, 178 Wright (W. B.), Peculiar Ice Formation, 534 Yellow Fever in Panama, 84 Yerkes Observatory, Report of the, Prof. Hale, 18 York, the Forthcoming Meeting of the British Association Yorkshire, the Making of East, a Chapter in Local Geo- Young (Grace Chisholm), the First Book of Geometry, Young (Prof. A.), an Artesian Well in the Karroo, 91 Young (W.), Rare Plants found in Scotland, 323 Zamabales, Negritos of, William Allan Reed, Dr. A. C. Zambesi Valley, the Stone Age of the, and its Relation in Zambesi, on the Zigzag Gorge of the, below the Victoria Zeidler (J.), die elektrischen Bogenlampen, deren Prinzip, Zemplén (Gyözö), Impossibility of Negative Impulse Ziegler (Dr. H. E.), die Vererbungslehre in der Biologie, Ziwet (Prof. Alexander), the Relation of Mechanics to Zodiacal Light to the North of the Sun, the, Prof. New- Zoogloa, Developmental Changes in, Dr. H. C. Bastian, Zoology: Extinct Animals, Prof. E. Ray Lankester, F.R.S., 6; Wild Swine of the Malay Archipelago, Dr. Habits of British Bats, A. Whitaker, 106; the Tarpan Zsigmondy (Richard), zur Erkenntniss der Kolloide, ueber Zwiers (H. J.), Ephemeris for Holmes's Comet (1892 iii., Hall (William), Tables and Constants to Four Figures, Harker (Dr. J. A.), Landolt-Börnstein-Physikalisch- History of Kingship, Lectures on the Early, Dr. J. G. Ireland, the Mammals of Great Britain and, J. G. Millais, Irrtum, Erkenntnis und, Prof. Ernst Mach, Supp. to G. M. Bell, Supp. to November 30, viii; a Text-book of Meyerhoffer (Dr.), Landolt-Börnstein-Physikalischchem- Millais (J. G.), the Mammals of Great Britain and Ireland, Mineralogy Precious Stones considered in their Scientific Origines de la Statique, les, P. Duhem, Supp. to November R. CLAY AND SONS, LTD., BREAD ST. HILL, E. C., AND BUNGAY, SUFFOLK. TWO TEXT-BOOKS ON MECHANICS. An Introduction to the Design of Beams, Girders, and Columns in Machines and Structures, with Examples in Graphic Statics. By W. H. Atherton. Pp. xiv +236. (London: Charles Griffin and Co., Ltd., 1905.) Price 6s. net. Mechanics for Engineers, a Text-book of Intermediate Standard. By Arthur Morley. Pp. xi + 282. (London: Longmans, Green and Co., 1905.) Price 4s. net. MR. R. ATHERTON'S book is for engineering students whose mathematical knowledge does not include the calculus. and such readers will find it a very useful source of information. The style is very unconventional-a trait which is rather helpful than otherwise--but occasionally the disregard of grammatical niceties and the ordinary rules of composition is carried too far. The author does not trouble himself in the least about discussions as to absolute and gravitation units of force and the so-called "engineer's unit of mass " (which is about 32.2 pounds). He is a practical engineer, as is sufficiently obvious from the words, "There are only two units of force that will be of much use to us-namely a pound for light work and a ton for heavy work "; but there is a suggestion of an ancient conundrum about his statement, "So far as we are concerned, force is measured in terms of some unit of weight, as that of a ton of iron." Chapter vi. contains a good exposition of the theory of the bending of beams, together with some useful cautions and explanations of certain discrepancies between theory and practice. The moments of resistance of beams of various cross-sections are all calculated by elementary non-calculus methods. The calculation of moment of inertia (the absurdity of which term the author very properly emphasises) is made in the same manner. It would be a great help to students--even to those who can use the calculus to give the particle rule for calculating all moments of inertia with reference to a triangular (and thence any polygonal) area; the moment of inertia of a triangular area about any axis whatever can be calculated by replacing the triangle by three equal particles at the middle points of the sides, their masses being represented by 4, where A area of triangle. = While the whole of the book will be found useful, the chapter on the comparative strengths of tubes of various forms may be specially mentioned. Mr. Morley's work differs from that above noticed in excluding all technical knowledge and terms, so that it is suitable to all students of dynamics, whether engineers or not. It does not employ a knowledge of calculus, its range being covered by algebra and elementary trigonometry, and its scope being that of the London intermediate engineering examination and that for the A.M.I.C.E. The work adopts the plan of founding the science of force on Newton's axiom ii., so that kinetical principles precede the treatment of equilibrium (statics). The great importance of the direct application of the principles of momentum and energy is recognised, at the outset by supplying a large number of excellent examples of these principles, so that the work is thoroughly modern in conception and method. There is a large and commendable use of squared paper diagrams for . calculating velocities, forces, work, &c., in cases in which these are variable according to other than the most simple laws. The poundal is, happily, not employed, but the 'engineer's unit of mass is adopted in order to save the definition of force, viz. "force is the rate of change of momentum." It is doubtful if many students are helped by this device, or if they really understand what they are doing when they say that the mass of a body is W/g. We must confine ourselves to a few brief observations on a work which we commend very highly. Is not a "knot " a speed -a geographical mile per hour? The newspapers sometimes speak of "20 knots an hour," so does the author (p. 20). It is a pity that he speaks of accelerating forces" (p. 43, &c.), because it is 66 1 essential to teach a student that acceleration is the 66 66 The A large collection of the ordinary statical problems is followed by a discussion of centres of gravity, moments of inertia and rotatory motions of rigid bodies, and a chapter on graphic statics, the whole being illustrated by a large collection of very well chosen examples. M. INDUCED RADIO-ACTIVITY. PROF. BASKERVILLE'S book is disappointing. fish itself was rendered radio-active, and, when placed on a photographic plate, photographed itself by its own radio-activity." As Prof. Baskerville, contrary to his usual custom, mentions no name in connection with this experiment, we assume that it is his own. None the less, we read, on pp. 92-93 : "Piffard calls attention to the fact that no authoritative statement has been given as to the rendering of water or other substances radio-active by the He further presence of a closed tube of radium. detected defects in tubes, air bubbles, &c., and regards the statements concerning induced activity by means of closed tubes as based upon the use of defective tubes. As Curie and Rutherford have shown, induced activity requires a naked exposure to radioactive bodies." For our own part, we have no belief in radio-activity having been produced in the fish under the conditions described. The photographic effects may have been due to imperfect closing of the tube of radium, or they may have been produced by some direct chemical effect of the fish's skin on the film. But however that may be, the author's attitude in emphasising equally two opposite statements is not intelligible. Prof. Baskerville has shown great industry in bringing together the results of different experimenters, but we cannot think that he has presented his collection judiciously. GARDEN CITIES. Garden Cities in Theory and Practice. By A. R. Sennett. Vol. i., pp. xix+557. Vol. ii., pp. xii+ 558. (London: Bemrose and Sons, Ltd., 1904.) Price 218. net. On opening a work on a scientific subject by an original worker in the field of which it treats ope expects to find the original materials thoroughly digested and worked up, and the relative merits of THES rival theories and conflicting experimental data carefully weighed; one hopes, too, to find novel suggestions for the interpretation of existing data, and hints to guide experimental research in the future. In the present work these things are not to be found. It may be said, broadly, that the book is no more than a collection of abstracts of original papers, put together, indeed, in some approach to a consecutive order, as regards subject-matter, but without the attempt to weld them into a homogeneous whole. We constantly find, for instance, that views which have no serious claims to attention, either from the authority of their authors or from the arguments they put forward, are treated with quite as much respect as the opposite conclusions of leading workers in the subject, which are supported by strong experimental evidence. In some cases the author even goes so far as apparently to endorse conclusions which are opposed to his own. On p. 88 we have a picture, underneath which the following explanation is given : "This is a radiograph of a gold fish which had been placed in water rendered radio-active by having suspended in it for 24 hours a closed tube (our italics) containing ten milligrams of radium of high activity. By this process the water was rendered radio-active, and the fish was then placed in the water, and, although the radium had been entirely removed, the HESE two handsome volumes represent the amplification of a paper on "The Possibilities of Applied Science in a Garden City " which was read by Mr. A. R. Sennett before Section F of the British Association in 1903. The author first deals very fully with the engineering problem involved in the laying out of garden cities. A comparison of the various plans on which the great cities of the world have been built is given in a most lucid and interesting manner, after which the author shows with many clear and convincing arguments that the best type is that known as the rectilinear configuration, which is the one he adopts -the worst of all being the curvilinear type, not only from an æsthetic, but also from a practical point of view. An interesting account of the rebuilding of London after the great fire is given in chapter ii. The various plans, especially those of Sir Christopher Wren and Sir John Evelyn, are fully discussed. The plan of the former was more or less adopted, although all his proposals were unfortunately not adhered to, with the result that many fine architectural effects are lost to the metropolis. We cannot do better than recommend those who are interested in this important subject to read the author's own account, which should excite interest even in the apathetic. regard to the spacing out of the area for his proposed garden city, the author has carefully considered every In detail. The proportion of the area to be occupied by the public thoroughfares, promenades, avenues, and private gardens is fully discussed. By a most ingenious and original plan of allotment, each house in the city stands in its own ground without being unduly overlooked or interfered with by neighbouring dwellings, but at the same time fitting harmoniously into the whole. Instead of the usual oblong or rectangular arrangement, the author subdivides the ground into polygonal or, more precisely, hexagonal plots. This he shows preserves a uniform frontage length, and at the same time admits of great elasticity as regards the size of the allotments which different inhabitants may desire. The city proposed by the author would consist of three separate areas, viz. the city proper, the village with its industrial zone, and the agricultural fringe. Each department is so arranged and laid out that the maximum amount of comfort and utility is combined with the minimum amount of expense. The city as a whole is so designed that it shall be self-supporting. All needless expense and extravagance are scrupulously avoided. The artisan's dwelling is made for the artisan, and the same applies to the housing of every grade and class of society. All are suitably provided for. Public buildings and offices, railway stations, &c., are grouped together within easy access of each other in the centre of the city. The sanitary and hygienic conditions of every kind are treated in an able and scientific manner. Every health-promoting device that ingenuity can suggest is brought forward in its proper place. It is beyond the scope of a review to mention these in detail. Suffice it to say that nothing is suggested which cannot be easily put into practice; and, further, many of the author's valuable and common-sense suggestions might with great advantage be adopted in our present cities. The sociological aspect of garden cities is treated in a rational and scientific manner. The doctrine of "equality which was urged by some when the site of the first garden city was acquired is relegated to its proper place by the author, who reminds his readers that the outcry for equality has proved the curse of industrial England, and points out the absurdity of ranking the "loungers--the quasi-inert and industrially passive atoms-as of equal national value to the active workers or energy-imparting unit." The decentralisation of industry is one of the great objects of garden cities-hence the authorities can deal with nothing below the industrial unit. Under the heading "Charity " the problem of dealing with the poor and infirm is discussed. The various pitfalls and dangers attendant upon indiscriminate charity are shown by actual examples. The problem is a serious one; but in this, as in other cases, the author finds a way of overcoming the difficulty, especially as regards garden cities which are untrammelled by established practice or tradition, and where methods such as the Elberfeld system, so successfully adopted in the town of that name and in Leipzig, and which the test of time--half a century --has proved to be sound in principle, might quite easily be put into practice. The work contains a wonderful amount of valuable information written in a readable style, while the illustrations are numerous, well chosen, and admirably reproduced. OUR BOOK SHELF. Elementary Experimental Chemistry. By A. E. Dunstan. Pp. viii+173. (London: Methuen and Co., 1905.) Price 2s. So many books on elementary chemistry have been published within the last few years that it is rather difficult to imagine why any more should be written, unless there is something strikingly novel in the style in vain in the little book before us. or matter of the book. For anything novel we search After being introduced to the metric system, in chapter ii. the student is supposed to find out the difference between chemical and physical changes by having to note the effect of heat upon sulphur, lead, magnesium, and sugar, and at the end of each experiment he has to state whether the change is physical or chemical. Chapter iii. deals with air, chapter iv. with active air. In chapter x. we come to solution, which to our mind would have been better treated earlier. Formulæ are not mentioned until p. 130, and on p. 131 the union of atoms to form molecules is shown in a diagrammatic manner which we venture to think will leave the student very little wiser than before. Almost all through the book the equations are written in words and not expressed in symbols, hydrogen. This is not necessarily objectionable in as, for example, zinc + sulphuric acid zinc sulphate + an elementary book, but to formulate all the equations which occur in the course of the book in an appendix is simply wasting type, because the student will never look at them. Furthermore, will the student understand the action of nitric acid upon copper by writing the equation in this manner? 2HNO, 2 NO } H2O+3Cu=2NO + H2O + 3CuO. 3 0 It is then explained that the copper oxide is acted upon by a further quantity of nitric acid, &c. Some of the experiments which the student is supposed to carry out are more for the lecture table than for the laboratory. For instance, on p. 121 the student has "to find the proportions in which oxygen and hydrogen combine to form water." Dry hydrogen and oxygen have to be collected in a eudiometer over mercury and then sparked. On p. 122 a similar experiment has to be carried out, but in this case to show the volume of steam formed. These are not experiments for elementary students, and we doubt whether the author himself allows his students to carry them out. The book is very fully illustrated, and some of the exercises are undoubtedly good, but for the book to be really useful to the student will require a considerable amount of discrimination on the part of the teacher as to what experiments the student can himself be trusted to work out. Wayside and Woodland Blossoms. By Edward Step; with coloured pictures by Mabel Step. First series, pp. xiii+176+127 plates. Second series, pp. xv+ 171+127 plates. (London: Frederick Warne and Co., 1905.) Price, each volume, 6s. net. ABOUT ten years ago Mr. Step prepared two handy little volumes which many country ramblers have |