172 



♦ KNOWLEDGE ♦ 



[June 1, 1889. 



blue by tbat careful observer, Dr. Gould, and they are all 

 sinsjle stars. If Mr. jNIonck objects to my quoting instances 

 from the southern hemisphere which he cannot verify 

 himself, I will refer him to the striking case of Vega, which 

 is a very blue star, and certainly has no companion brighter 

 than itself. The small companion is also decidedly redder 

 or lower in the spectrum than the principal star. I do not 

 take such exception to Professor Young's statement, which, 

 it should be noted, diflers from Sir John Herschel's, for 

 Professor Young confines his remark to double stars, and 

 says that tlie smaller always lies higher in the spectrum. 

 Yega is probably not an exception to this rule, as we do not 

 know it to be double, and theie is probably not any physical 

 connection between it and its minute companion. But 

 Sirius, which is an undoubted binary, is bluish- white, while 

 its companion is reddish and cannot be described as highei' 

 in the spectrum than the principal star. The general law 

 is, however, well worthy of remark, but we shall not lose 

 by eirefully noting the exceptions. 



A. C. Pi.^NYARD 



^otirts of 35ook5» 



The Bloivpipe in Chemistry, Mineralogy, and Cleology. 

 By Lieutenant-Colonel W. A. Ross, R.A. Second Edition. 

 (London : Crosby Lockwood ife Son. 1889.) — Colonel Ross 

 is an enthusiastic blowpipe manipulator, and has done 

 much service in popularising blowpipe analysis. The book 

 cont.ains descriptions of many varieties of blowpipe ap- 

 paratus and appliances, and it is satisfactory to find that the 

 author recommends simple and cheap as opposed to elaborate 

 apparatus. As an advocate of hand, foot, and reservoir 

 blowers as compared with the ordinary mouth blowpipe, he 

 will be welcomed by many who, with out- blown cheeks, 

 have lost patience, time, and breath in vainly endeavouring 

 to fuse a refractory assay. The theory of the blowpipe 

 flame is dwelt on ; we are told that it is a solid cone of 

 flame, and the oxidising and reducing flames of our youth 

 are banished in favour of " oxyhydrogen " and "hydro- 

 carbonous pyrocones " respectively, whilst our coloured 

 blowpipe flames become " pyrochromes," a phraseology 

 which contrasts curiously with the simplicity of the 

 apparatus he recommends. That excellent and useful 

 introduction of the author's — the aluminium plate support 

 — is described, and its application to blowpipe assays ex- 

 plained. Many tables of rocks, minerals, ores, silicates, etc., 

 showing their composition and their behaviour before the 

 blow|5ipe, are interspersed thi-ough the book, and will be 

 found useful. Whilst admiring the author's enthusiasm for 

 the methods ho has elaborated, we think that for purposes 

 of instruction a terser st\ le would have been better. The 

 specific gravitometer, which he describes on p. 116, cannot 

 be recommended, for one reason among others, the air can- 

 not be satisfactorily expelled from the little box containing 

 the gold dust, kc. 



A Ttxt-hook of Elementary Metallurgy. By Arthur 

 H. HioRNs. (Macmillan & Co. 1888.) -This little work 

 has been arranged to meet the requirements of pupils pre- 

 paring for the elementary stage of the Science and Art 

 Department's examinations in metallurgy. In the first 

 three chai)ters, which are more or less introductory, the 

 technical terms in general use are defined and a description 

 is given of the nature and properties of fuel. The usual 

 methods of extracting the useful metals from their ores are 

 explained, and sectional drawings of the various furnaces 

 are given, as well as explanations of several iron and steel 

 processes— Freibeg's process for silver, and the Welsh 

 methods for copper. The book is written in a clear and 



simple manner, and can be recommended as a valuable 

 addition to our elementary manuals. 



Celestial Motions ; a Ilamly Book of Astronomy. By 

 W. T. Lynx, B.A., F.lt.A.S. Sixth Edition. (London : 

 E. Stanford.) — -The fact that in five years Mr. Lynn's little 

 treatise has gone through as many editions is a proof of its 

 popularity with the scientific public. There are many 

 decided improvements in the present edition, the work has 

 been considerably enlarged, a chapter on the Calendar 

 added, and the eight pages giving a list of the asteroids 

 have been omitted, we think with advantage. Perhaps 

 some reference to more recent investigations on the proper 

 motion of the solar system than those of Airy and Dunkin 

 might have been introduced, at lea.st .some notice .should 

 have been taken of Ludwig Struve's recent rese?irches, 

 based on the proper motions of more than 2, .500 stars. The 

 results of Peters's and Elkin's determinations of the parallax 

 of Capella give a far smaller parallax than 0"*3, Elkin 

 giving 0"'ll and Peters 0''-07, corresponding to thirty and 

 seventy-one light years respectively, while Struve's value 

 gives a distance of only eleven light years. But with these 

 exceptions, Mr. Lynn's work appears to be very carefully 

 and accurately brought^up to date. 



Chambers's Encyclopeedia.* — The.se volumes swell the 

 evidence that Messrs. Chambers follow with unslackening 

 zeal the traditions of their house iu its honourable dis- 

 tinction of supplying high-class " information for the 

 people " at a price which brings it within the means of 

 the cottager. Our general survey — for only this is possible 

 — of the articles in these instalments of a work the com- 

 pletion of which we await with eagerness justifies us in 

 saying that the lofty standard of the first volume is 

 maintained, and that where the articles may need i-evision, 

 this will be only in virtue of that advance in knowledge 

 which makes periodical recasting of all encyclopiedic works 

 necessary. Many of the articles, notably the biographical, 

 will escape this, since their crisp presentment of facts and 

 sound assessment of their several subjects render them 

 final and complete. Mr. Davidson's general I'emarks 

 under the head " Biogr.aphy " are sound and discriminat- 

 ing, except where he gives even qualified commendation to 

 that worthless piece of slop-work, Trollope's " Life of 

 Thackeray ; " and among the more admirable articles of the 

 kind we may note Sir Geo. Grove's " Beethoven," Whyte's 

 " Boccaccio," Andrew Lang's " Burns," with that undue, 

 prominence of the warts and wrinkles of the man which is 

 also given in the " Letters to Dead Authors," Ornsby's 

 " Cervantes," and Grant Allen's " Darwin." The article 

 on " Buddhism " has been subjected to needful revision, the 

 expcsition of the doctrines of karma and nirvana being as 

 clear as the obscurity of those theories permits. Nir- 

 vana is defined as includiug other ideas than those of 

 annihilation, corresponding, as Rhys Davids has shown, 

 to the Pauline " peace of God which passeth under- 

 standing." The biological articles, as might be expected 

 from their writer's attainments, are masterpieces of 

 lucidity and exactness, and it is surprising that under such 

 limitations of space as the work imposes, Mr. Patrick 

 Geddes should have contrived room for dainty and sug- 

 gestive paragraphs such as the following, which adorns the 

 article on " Botany." Speaking of the narrowing iiifluence.s 

 of mere fact-collecting, apart from care as to the significance 

 of the things collected, he says : — 



The highest modem botany neither harvests plants with the 

 herbalist, nor picks them to pieces with the child, but finds alike its 

 rise and climax in watching the blossoms open and the bees come 

 and go. The pedigree of the science is only on one side, from the 



* Vol. II. Bea to Cata. Vol. III. Cata to Dion. (London and 

 Edinburgh : W. & R. Chambers, 1888-1889). 



