388 



NA TURE 



[February 24, 1898 



and ventilate them by open covers at street level. Sub- 

 sequent to this, and up to the year 1886 the typhoid 

 death-rate showed a most remarkable decrease, falling 

 during this period at its lowest to 16-3 per 100,000. 

 Yielding, however, to the pressure of numerous public 

 complaints about the obnoxious smells rising from the 

 sewers in the various thoroughfares of the town, the 

 Sanitary Committee decided in 1886 to close the open 

 street ventilators, and to erect in their place cast-iron 

 pipes up the sides of houses wherever the necessary 

 permission of the house-owners could be obtained. 



Since 1886, also, improvements have been made in the 

 sewerage system of the town, for the old and small main 

 sewers have been replaced by larger and better con- 

 structed ones at a cost of nearly 200,000/. ; but in spite of 

 this and other sanitary improvements, the typhoid death- 

 rate has actually risen in Leicester during this latter 

 period. Felix qui potuit rerum cognoscere causas ! 



It must indeed be frankly admitted that our knowledge 

 of the conditions — and there may be many factors, which 

 determine outbreaks of epidemic disease — is at present 

 in some respects hopelessly inadequate. No more con- 

 clusive example of this is to be found than is presented 

 by the diphtheria epidemic which has taken such a firm 

 hold of London, and which has also manifested itself 

 in various other parts of the country, and, despite 

 all the boasted hygienic enlightenment of the closing 

 years of the century, pursues its triumphant course prac- 

 tically unchecked. 



Sewer gas may be charged with a great deal, but we 

 also know that other factors — as, for example, infected 

 water and milk — are also heavily weighted with re- 

 sponsibility in the dissemination of disease, and that to 

 shift the whole burden of a particular epidemic upon 

 any one single factor becomes the more unreasonable 

 the wider our scientific horizon is extended. 



G. C. Frankland. 



OUR BOOK SHELF. 



Chambers's Algebra for Schools. By William Thomson, 

 M.A., B.Sc, F.R.S.E. (London : W. and R. Chambers, 

 1898.) 



This is a plainly written and well-arranged book of 

 secondary grade, quite worthy of the crucial test which 

 only practical teachers can apply. Among its praise- 

 worthy features may be mentioned the attention paid to 

 degree, homogeneity, and symmetry ; the early introduc- 

 tion of the method of detached coefficients ; and the 

 elementary discussion of graphs. The chapter on indices 

 is more satisfactory than is usually the case in works of 

 this kind ; on the other hand the chapter on surds is 

 disappointingly conventional, and that on logarithms 

 might certainly be revised with advantage. All logarithmic 

 calculations ought to be printed in the form in which a 

 computer would write them down on paper ; explanations, 

 of course, may be added when necessary. 



The chapter on the binomial theorem for any exponent 

 is not satisfactory : it would be much better simply to 

 state the conditions under which the theorem is true, and 

 to give some numerical examples to illustrate the use of 

 it for purposes of approximate calculation. 



The examples are numerous, and there is, on the whole, 

 a refreshing absence of those fantastic absurdities which 

 are never found except in text-books and examination 

 papers. In the examples on variation, illustrations 

 derived from physics might very well have been inserted: 



NO. r478, VOL. 57] 



the same thing may be said about the examples on 

 equations. 



It is probably useless to protest against the method of 

 solving quadratics by completing the square ; like the 

 Imperial system of weights and measures, it has become 

 a national fetish, and its cult is proof against all the 

 arguments of common sense. G. B. M. 



Die Kraft utid Materie im Raume. Grundlage einer 



neuen Schopfungstheorie. By A. Turner. Fifth edition. 



Pp. xxiv -1- 407, and 20 plates. (Leipzig : Theod. 



Thomas, 1897.) 

 In his preface to the present edition of this work the 

 author remarks : — 



"We have given positive proofs of the untenability 

 and the imaginary foundation upon which rest the 

 hypotheses which have for their subject-matter the theory 

 of vibration of a cosmic ether, whether these relate to 

 light, heat, or to the artificial terms under the aegis of 

 ' the conversion of work into heat, energy into electricity, 

 &c.,' in short the greater part of the hypotheses which 

 form the foundation and chief support of the privileged 

 sciences of to-day. 



"They represent no scientific truths, but, together 

 with the catch-words indicated, serve merely as a cloak 

 for ignorance, their supporters having no suspicion of 

 the nature or true inwardness of the phenomena in 

 question or of their causal connection." 



Turning to the body of the work we find, expressed in 

 somewhat similar style, a theory of the universe postu^ 

 lating matter and space as ultimate realities. Matter 

 consists of centres of force attracting or repelling each 

 other when they approach each other within certain 

 limits. Light is the impression made on the optic nerve 

 by radiant matter. The phenomena of heat are due to 

 the repulsion of one substance by another, and so on. 

 At the end of the book 150 theses are printed for the 

 convenience of those who feel impelled to combat the 

 author's views. 



The Observer's Atlas of the Heavens. By William Peck, 



F.R.A.S., F.R.S.E. Charts 30 ; pp. 32. (London 

 ■ and Edinburgh : Gall and Inglis.) 

 This volume contains catalogues giving information 

 relating to double stars, variable stars, nebulae, and other 

 celestial bodies, together with thirty star charts in which 

 the positions of nine thousand objects are shown. 



The charts include the whole celestial sphere, and are 

 drawn to a large scale, five degrees of a great circle 

 being equal to one inch. They are arranged so that, 

 as far as possible, each constellation is shown complete 

 in itself. The scale of magnitudes is well chosen, the 

 stars appearing with the same relative importance on 

 the charts as in the heavens. The practical value of 

 the atlas would be greatly enhanced, however, if a scale 

 of magnitudes were attached to each chart. 



The brighter stars, down to the third magnitude, are 

 shown to a half, and fainter stars to a whole magnitude. 

 To facilitate identification in the various catalogues, 

 either a letter or Flamsteed number is attached to every 

 important star. A commendable feature is the insertion 

 of the various data, from which the charts were com- 

 piled, in the form of catalogues of the different celestial 

 bodies. These catalogues will be found very useful, and 

 include such information as the magnitudes of the 

 brighter stars to the nearest tenth, and the positions of 

 stars down to the fourth magnitude, with their Flamsteed 

 and British Association numbers. 



Other useful information is included, such as diagrams 

 showing the appearances of over one thousand double 

 stars when near the meridian, and a chart of the moon 

 with an index. 



Undoubtedly, this atlas will be found very useful by 

 astronomical oljservers, especially amateurs, for whose 

 requirements it seems to be particularly designed. 



