McDowall. Pp. xvi+155. (Cambridge University Press.) 38. net. Insect Workers. By W. J. Claxton. Pp. xii+62. (London: Cassell and Co., Ltd.) IS. net. Wild Life and the Camera. By A. R. Dugmore. Pp. xi+332. (London: W. Heinemann.) 6s. net. The Charm of the Hills. By S. Gordon. Pp. xiv + 248. (London: Cassell and Co., Ltd.) Ios. 6d. net. A Geography of the British Empire. By Prof. A. J. Herbertson and R. L. Thompson. Pp. 256+3 maps. (Oxford: Clarendon Press.) 2s. 6d. The Lost World. By A. Conan Doyle. Pp. 319. (London: Hodder and Stoughton.) 6s. The Home Life of the Terns and Sea Swallows. By W. Bickerton. Pp. 88+32 plates. Witherby and Co.) 6s. net. (London: Radium and Radio-activity. By A. T. Cameron. Pp. 185. (London: S.P.C.K.) 2s. 6d. Astronomy. By Dr. F. W. Dyson. Pp. vi+118. (London: J. M. Dent and Sons, Ltd.) 18. net. On the Consciousness of the Universal and the Individual. By Dr. F. Aveling. Pp. x+255. (London: Macmillan and Co., Ltd.) 5s. net. The Science of Illumination. L. Bloch. By Dr. Translated by Prof. W. C. Clinton. Pp. xiv + 180. (London: J. Murray.) 6s. net. Pp. A Handbook of Physics. By W. H. White. xv+667. (London: Methuen and Co., Ltd.) The Prehistoric Period in South Africa. By J. P. Johnson. Second edition. Pp. 115+ plates. don: Longmans and Co.) IOS. (Lon the Edible Mussel (Mytilus edulis): Dr. H. Lyster Jameson and Dr. W Nicoll. Descriptions of l'hree New Fishes Discovered in the Gold Coast by Dr. H. G. F. Spurrell: G. A. Boulenger. MINERALOGICAL SOCIETY, at 5.30.-Ilmenite from the Lengenbach Quarry, Binnenthal: Prof. W. J. Lewis.-An Account of the Minerals found in the Virtuous Lady Mine, near Tavistock: A. Russell.-Some Graphical Methods in Crystallography and Crystal Optics: A. Hutchinson.Labradorite from Co. Down: A. Hutchinson and W. Campbell Smith. Apparatus for Preparing Thin-sections of Rocks: Dr. G. F. Herber Smith.-Calcite Crystals from a Water Tank: R. F. Gwinnell. THURSDAY, NOVEMBER 14. ROYAL SOCIETY, at 4.30.-Probable Papers: The Development of a Parasite of Earthworms: J. W Cropper.-Further Contribution to the Study of the Inheritance of Hoariness in Stocks (Matthiola): Edith R. Saunders. The Influence of Temperature on the Absorption of Water by Seeds of Hordeum vulgare in Relation to the Temperature Co-efficient of Chemical Change: Prof. A. J. Brown.-Note on Merlia normani and the "Monticuliporas": R. Kirkpatrick.-The Chemical Action of Bacillus cloacae (Jordan) on Citric and Melic Acids in the Presence and Absence of Oxygen James Thompson.-The Origin and Destiny of Cholesterol in the Animal Organism. X. The Excretion of Cholesterol by Man, when Fed on Various Diets: G. W. Ellis and J. A. Gardner.-The Comparative Anatomy and Affinities of the Araucarineae: Prof. R. Boyd Thomson. And other Papers. INSTITUTION OF ELECTRICAL ENGINEERS, at 8.-Address by the President (W. Duddell.)-Presentation of Premiums. CONCRETE INSTITUTE, at 7.30.-Presidential Address: E. P. Wells. MATHEMATICAL SOCIETY, at 5.30. Annual General Meeting. - Presi dential Address on Recent Advances in the Theory of Surfaces: H. F. Baker. Some Properties of Cubic Surfaces: A. B. Grieve.-The Determination of the Summability of a Function by means of its Fourier Constants: W. H. Young.-Groups of Linear Substitutions of Finite Order which Possess Quadratic Invariants: W. Burnside.-The Irreducibility of Legendre's Polynomials: J. B. Holt.-The Representation of a Summable Function by means of a Series of Finite Polynomials: E. W. Hobson.-Theory of Functions of Real Vectors: E. Cunningham. FRIDAY, NOVEMBER 15. ROYAL GEOGRAPHICAL SOCIETY, at 8.45.-The Norwegian South Polar Expedition: Capt. Roald Amundsen. DIARY OF SOCIETIES. THURSDAY, NOVEMBER 7. ROYAL SOCIETY, at 4.30.-Radiation and Absorption of Light in Gaseous Media, with Applications to the Intensity of Sky Radiation: L. V. King.-A Standard Measuring Machine: Dr. P. E. Shaw.-A Spectrophotometric Comparison of the Emissivity of Solid and Liquid Gold at High Temperatures with that of a Full Radiator: E. M. Stubbs and Dr. E. B. R. Prideaux.-Optical Properties of Substances at the Critical Point: C. Smith.-Absorption of Helium and other Gases under the Electric Discharge: Hon. R. J. Strutt.- (1) The Discharge between Concentric Cylinders in Gases at Low Pressures; (2) The Influence of the Nature of the Kathode on the Length of the Crookes Dark Space: F. W. Aston. -The Determination of the Absolute Unit of Resistance by Alternating Current Methods: A. Campbell.-Some Unclassified Mechanical Properties of Solids and Liquids: A. Mallock.-Trichromatic Theory of Colour Vision. The Measurement of Fatigue of the Retina : Sir W. de W. Abney, K.C.B. FRIDAY, NOVEMBER 8. ROYAL ASTRONOMICAL SOCIETY, at 5.-The Constitution of the Solar Corona. III. J. W. Nichols n.-Telescope Finders: T. K. Mellor.-Suggested Application of Mr. Innes's Formula for Magnitude of Double Stars to Observations of Certain Variable Stars: M. E. J. Gheury.(1) The Sun-spot Minimum: Sun-spots and Prominences, 1912, October 10; (2) Sun-spots and Magnetic Phenomena, 1848-1911. The Cause of the Annual Variation in Magnetic Disturbances: Rev. A. L. Cortie.-The Transit of Mercury in 1707: G. van Biesbroeck.-The Light-source of the Andromeda Nebula J. H. Reynolds.-Note on the Oxygen Triplet of the Infra-red of the Solar Spectrum: Royal Observatory, Edinburgh.-(1) Spectrographic Observations of the Sun's Rotation at Cambridge Observatory; (2) A Method of Measuring Spectrograms with the Help of a Cylindrical Lens: J. B. Hubrecht.-The Sidereal System: Revision of 1912 (continued) Maxwell Hall.-Probable Paper: Note on the Magnitude of Nova Geminorum: H. Jameson. PHYSICAL SOCIETY, at 8.-- On a Method of Measuring the Thomson Effect: H. R. Nettleton.-An Improyed Joule Radiometer and its Applications: F. W. Jordan.-Note on the Attainment of a Steady State when Heat Diffuses along a Moving Cylinder: Miss A. Somers.-The Thermomagnetic Study of Steel: S. W. J. Smith. MALACOLOGICAL SOCIETY, at 8.-Tivella and Grateloupia: A. J. JukesBrowne. Some Remarkable Shell Monstrosities: G. C. Robson.New Mollusca from the Marine Tertiary Deposits of the North Pacific Coast of America: Ralph Arnold and Harold Hannibal.-Descriptions of new species of Limicolaria and Krapfiella from East Central Africa: H. B. Preston. TUESDAY, NOVEMBER 12. INSTITUTION OF CIVIL ENGINEERS, at 8.-The Construction of the New Dock at Methil: B. H. Blyth. -Alterations and Improvements of the Port Talbot Docks and Railway during the Last Decade: W. Cleaver. ROYAL ANTHROPOLOGICAL INSTITUTE, at 8.35.-Some unrecorded Customs of the Mekeo People of British New Guinea: R. W. Williamson. ZOOLOGICAL SOCIETY, at 8.30.-Some Falkland Island Spiders: H. R. Hogg. Some Points in the Anatomy of the Mouth-parts of the Mallophaga: Bruce F. Cummings.-Contributions to a Study of the Dragonfly Fauna of Borneo. I. The Corduliina: the Genus Amphicnemis F. F. Laidlaw.-Some Parasites of the Scoter Duck (Oedemia nigra) and their Relation to the Pearl-inducing Trematode in THURSDAY, NOVEMBER 14, 1912. ELECTRONS AND THE ELECTRO- Electromagnetic Radiation and the Mechanical PROFES They In the appendices several theorems are proved which lead up to an interesting discussion of the possible mechanical explanations of the electron. It is shown that the Lorentz deformable electron is more easily explained mechanically than the electrons of Abraham and others, as it only requires an invariable hydrostatic pressure of the æther over its surface to enable it to subsist. This pressure is estimated (p. 269) as 1025 atmospheres. Moreover, the mass-formula for such an electron is practically the only one which can be applied in the mathematical theory of the mechanical forces and the radiation. By Dr. G. A. Schott. Pp. xxii+330. (Cambridge University Press, 1912.) Price 18s. net. OROF. SCHOTT'S original essay is, in this book, supplemented by a series of valuable appendices, which amply justify the delay in its publication. The work is deductive in plan; its foundations are the electromagnetic equations of Maxwell and Hertz, together with the LarmorLorentz expression for the mechanical force on a moving charge. The "retarded potentials" of the electromagnetic field are transformed so as to yield Schott's solutions, in the form of "modified Fourier integrals," and most of the calculations are performed from these as starting point. lead simply, and with considerable mathematical rigour, to many results obtained by other writers; in particular, the "point laws" of Liénard and Wiechert are deduced, and are used to illustrate the general features of the electromagnetic field in a number of special cases. The exact calculations, however, are more readily executed with Schott's expressions, and various simple cases of motion of electrons are thus dealt with, as, e.g., uniform or uniformly accelerated rectilinear motion. Periodic motions, such as uniform circular motion of a single electron, or of a ring of electrons, are also discussed. More complex cases, like pseudoperiodic or aperiodic motions, cannot be solved completely, but the distant field is approximated to. Specially interesting are the problems relating to the pulse theory of the X-rays, and the precessional (1) Common Land and Inclosure. By Prof. E. motion of a ring of electrons, as applied to Ritz's theory of the Zeeman effect. The velocities of the electrons are not restricted to be less than the velocity of light, chiefly because the mathematical expressions require no such condition (though the work is far simpler in the restricted case). It is pointed out that no experimental evidence, either way, has been brought to settle the question of the possibility of velocities exceeding that of light; if the Lorentz formula were universally true, indeed, the question would be decided in the negative, but this formula has been verified (by Bucherer) only for velocities considerably less than that of light. Moreover, the theory of relativity, which is based on this formula and has proved useful in explaining aberration phenomena and the behaviour of moving optical systems, neglects the loss of energy For the mathematician the book abounds in problems and suggestions of interest and importance; especially does it clearly display the need for the cooperation of the pure analyst in the study of the summation and convergence of the difficult series and integrals which occur in its investigations. The physicist will, perhaps, find it rather tedious to unearth the physical conclusions (which are pointed out from time to time in the course of the work) from the mass of complicated mathematics in which these remarks are involved. The great value of the book would have been increased if the physical bearing of the results had been summarised in an extra chapter; this is done to a slight extent in the preface. A greater number of numerical calculations would also have been advantageous in giving a clearer grasp of the results, but the great labour required for such an undertaking sufficiently explains the omission. THE LAND AND ITS LORE. C. K. Gonner. Pp. xxx+461+5 maps. (London: Macmillan and Co., Ltd., 1912.) Price 12s. net. (2) Byways in British Archaeology. By Walter Johnson. Pp. xii+529. (Cambridge: University Press, 1912.) Price 10s. 6d. net. CIENTIFIC studies of the history of landholding have a peculiar importance at the present moment, when legislative innovations in ownership are so widely mooted on a priori grounds. By supplying valid inductions from the past, science here, as in other spheres, provides the statesman with a solid foundation for political principles, and a sure test for fallacious schemes. The entire history of English agriculture, so far as it is connected with national progress and advance in civilisation, is bound up with "common" and inclosure, and the passage from the former to the latter. The land question, it is not too much to say, cannot be begun to be understood until this relation has been worked out. "Common" in early times was “in entire contrast to the ideas associated with it in the present day. . . . Its existence now is taken as denoting the claims, somewhat vague and precarious, of the public as against those holding the land and engaged in its cultivation. But this finds no sanction in a time when . . . common was a result of a claim to land, and formed a necessary con dition of its proper management. . . The early rights of common were anything . . . rather than a general claim on the part of the public. . . . The common right was an essential part of agriculture, and it was only as, owing to changes in circumstances, this became less apparent, that casual profits and gains and the so-called rights of the poor, these latter being in many instances a trespass and not a right, came to be important." Thus Prof. Gonner defines his subject. The history of the method of common and of the gradual progress of inclosure occupies two-thirds of the volume. The rest is devoted to the effects of the evolutionary change. Inclosure is part of "a wider economic movement." Its "beneficial effect on farming is undoubted . . . particularly in the increased utilisation of what is, after all, the distinctive agricultural wealth of England, rich grazing and dairy lands." Of particular importance is its connection with "the change whereby agriculture, from being a means of subsistence to particular families, had become a source of wealth to the nation." It is particularly interesting to the sociologist to note that rural population "did not vary with inclosure, and that this movement was not, at any rate, the main cause of the increase in poor relief expenditure." No Prof. Gonner has written an invaluable study, which is final, and should become a classic. sociologist and no statesman can afford to ignore it. (2) The author of "Folk Memory" devotes 400 pages to answering the question: In what ways may the church-fabric be regarded as the social centre of early English life? There is abundance of original observation, and in in controverted matters, such as round towers, the author's judgment is eminently reasonable. For he treats these radiating paths of folklore-they are this rather than byways from a wide sociological outlook. In "The Folklore of the Cardinal Points," and "The Labour'd Ox," he treats new ground. "The Cult of the Horse" is an interesting compilation of palæontological data and early English horselore. The "White Horse," and what amounts still to a tabu against eating horseflesh, receive ENGINEERING HANDBOOKS. (1) Reference Book for Statical Calculations (Rapid Statics), Force-diagrams for Frameworks, Tables, Instructions for Statical Calculations, &c., for all Classes of Building and Engineering. By Francis Ruff. Pp. 136; illustrated. Vol. i. (London: Constable and Co., Ltd., 1912.) Price 4s. net. (2) Les Nomogrammes (2) Les Nomogrammes de l'Ingénieur. By Ricardo Seco de la Garza. Avec une Préface de Maurice d'Ocagne. Pp. xii+ 195 +85 plates. (Paris: Gauthier-Villars, 1912.) Price 12 francs. (3) Laboratory Instruction Sheets in Elementary Applied Mechanics. By Prof. A. Morley and W. Inchley. Pp. v+50. (London: Longmans, Green and Co., 1912.) Price Is. 3d. net. (4) A Handbook on the Gas Engine. Comprising a Practical Treatise on Internal Combustion Engines. By Herman Halder. Translated from the German and Edited by W. M. Huskisson. Pp. xii+317. (London: Crosby Lockwood and Son, 1911.) Price 18s. net. (5) Concrete Costs. Tables and Recommendations for Estimating the Time and Cost of Labour Operations in Concrete Constructions and for Introducing Economical Methods of Management. By Dr. Frederick W. Taylor and Stanford E. Thompson. First edition. Pp. xxii +709. (New York: John Wiley and Sons; London: Chapman and Hall, Ltd., 1912.) Price 215. net. (1) THE HE usual graphical methods for determining the stresses in framed structures form the subject of this little book. With the exceptions of the wind pressure on roof trusses, the load on a framework column, and pressure upon retaining walls, the structures are subjected to symmetrical loads concentrated at the joints. Each form of roof, bridge truss, girder, or cantilever occupies a separate page, together with its reciprocal figure, the construction of the force polygons being described on the opposite sheet. There are some thirty examples of the usual forms of truss, covering the ordinary cases that occur in engineering practice. The method adopted of forming the reciprocal figures loses much by the notation employed, and is far less satisfactory than Bow's notation, in which the spaces between the members of a structure are designated by a letter or numeral. The concluding third of the book contains a short dissertation on reinforced concrete (in which the ratio of the moduli of elasticity of steel to concrete is taken at the low value of 10), and this is followed by tables usually found in engineers' handbooks on the geometrical properties of structural shapes, such as moments of inertia. There are many blemishes due to imperfect translation, and we find such expressions as "10-fold security" for "factor of safety of ten." The translation does not extend to weights and measures, which are in the metric system. (2) The preface to this volume is, for the most part, a reprint of remarks made by M. Maurice d'Ocagne, Ingénieur en chef des Ponts et Chaussées, at the Fourth International Congress of Mathematicians, in Rome, 1908. In this paper he defines the word "nomogramme," which is probably new to most English mathematicians, the nearest English equivalent being an abacus, known as an instrument for performing calculations by balls sliding on wires, which are still employed in Russia, China, and Japan. M. d'Ocagne has brought forward this system of graphical calculation by published researches extending over twenty-five years, and the author of this work employs the method for solving problems in military engineering, though many of the examples are of wider application, and are of extended use in the solution of equations of three or four (or more) variables. The interest in the work would therefore lie chiefly in the method as such, the particular applications of the method to the solution of equations used by the military engineer being of secondary importance, though, as a handbook for rapid calculation within the limits of the chosen field of utility, it would certainly serve a useful purpose to many. The reader will doubtless find himself constructing nomogrammes to suit particular problems of his own, and thus the work before us is extremely suggestive, and a fruitful stimulus to the use of a graphical method of varied application. There are eighty-five nomogrammes in the work, each on a separate sheet and consisting for the most part of straight lines upon which divisions are marked. A loose celluloid sheet marked off in rectangular coordinates is provided for laying upon the nomogramme, and upon placing it in such a position that the known values of the variables in the equation are cut by the lines, the value of the unknown variable may be ascertained by intersection upon the scale provided for that variable. Thus, for example, the solution of plane triangles may be taken as being a problem of general application. Given the two sides and included angle, the opposite side (a) may be found. directly by the application of the rectangular coordinates to the nomogramme; in other words, the equation a2 = b2 + c2 — 2ab cos A may be solved for all values of b, c and A. Besides the usual problems in mensuration, the safe loads on columns for given values of the ratio of length to least radius of gyration for various materials, the bending of beams, stresses in roof trusses and bridges and numerous other problems may be solved without calculation. The printing of the scales on the nomogrammes leaves much to be desired, but the work as a whole is a most interesting contribution to graphical methods of solution. (3) This little book is made up of twenty-five single perforated sheets bearing upon each a concise description of a simple laboratory experiment in applied mechanics with an illustration of the apparatus. The experiments are of the usual kind for the elementary mechanical laboratory and comprise statics, efficiency of lifting machines and friction, forces in braced structures, moduli of elasticity, spring vibrations, pendulum, and others. Prof. Morley states that they are selected from instruction sheets used in his laboratory, and nay be usefully employed in conjunction with his textbooks on elementary applied mechanics. However opinions may differ concerning the expediency of giving a student cut-and-dried directions concerning his laboratory work and leaving little to his own judgment and talent, those who favour this plan of instruction will find all that they desire in these well-arranged experiments. It saves much time and needless explanation on the part of the demonstrator to have the experiments written out, and as these are selected by experienced teachers they should prove useful in the elementary laboratory. (4) This work contains a mass of constructional detail on the gas engine which should find favour with engineers and draughtsmen engaged in the design of such motors. It represents the results of much practical experience, and on the part of both the author and translator it shows a very careful scrutiny of the best engineering practice. The thermodynamics of the subject is somewhat neglected, but this omission is counterbalanced by the exhaustive treatment of the forces developed by the engine when running. The effect of the inertia of the reciprocating parts, turning moment. diagrams for calculating fly-wheel masses, and balancing, are discussed with the view of assisting the draughtsman in his design, and the effects of various combinations of cylinders receive more attention than usual in works of this kind. Minute details are set forth with painstaking care, and there is no part of the anatomy of the engine which has not a place in the work. Metric measures have been converted by the translator, but the tabulated dimensions of Continental engines have been retained in millimetres in parallel columns. (5) The cost of mixing and laying concrete is essentially governed by local circumstances, and it would be unsafe to generalise from isolated results, however carefully they may have been collected. The authors have been at great pains to collect information based upon work done in the United States, and no doubt with due allowance for the difference in the cost of labour and materials and the varying rate of output of work, much of their conclusions would be applicable to other conditions and places. But the work is not wholly confined to questions of cost, for it contains much valuable, if incidental, information concerning the making of concrete in bulk, form of moulds, reinforcement for ferro-concrete and other matters pertaining to construction in this material. It is to be regretted that so much prominence was given to costs, though the title of the work very clearly points to this as the dominant feature. Nevertheless, with due allowances, as a reference book there is much in it for the architect and engineer, and it is eminently satisfying to know that the figures were obtained by close application and systematic study of construction work for many years. OUR BOOKSHELF. there may be difference of opinion, especially with Compendio Elemental de Zoología. By Angel PROF. ÁNGEL GALLARDO has prepared a useful Pp. Price Manual Training Woodwork Exercises Treated As to the desirability of adopting this course As IN twelve short sections devoted to the respective |