M\v I'in. 



KXOWLEDGl-: 



203 



with a cliapter on the balance, followed by hydrostatics, 

 properties of matter, determination of densities, and finally the 

 main properties of matter in the jjascons state. The book ends 

 with a valuable np-to-date chapter on pnmps. A f F 



I'liysicdl MLUisiirciiiciifs. — B\- A.W. Dvvv .and .\. W. K\vi-:i.i . 

 25S pa;;es. 7iS illnstrations. .Sl-in. X 5'-in. 



IJ. S.S; A. Chnrchill. Price 7 6 net. I 



The bool< will be a great help alike to those taught and to 

 the teacher. In the first case the book is not too long, not too 

 minute in detail, but the descriptions are concise and to the 

 point. In the second case the book covers a fairly wide field, 

 so that it aids the teacher in selecting e.xperimental studies for 

 any particular class of students, .\nother valuable feature is 

 its numerous references both to practical treatises such as 

 Kohlrausch's " Physical Measurements." and also to smaller 

 class text books. 



In the introduction, which .gives general advice as to the 

 taking of observations, their possible and probable errors, and 

 the plotting of curves, occurs this sentence: — '' Much time in 

 the laboratory will be wasted unless some preparation be made 

 before coming to the laboratory .... this may usually 

 be done at home in a few minutes, whereas it might require an 

 hour or more in a labor.itorx- where a number of people are 

 moving around." This is very true. The man who is 

 researching would not come to the laboratory and spend half- 

 au-hour picking up the thread of the previous day's work ; he 

 comes generally' with a fi.xed intention of trying some particular 

 experiment which he has carefully planned out. So, too, it 

 should not be that the student should have to spend much 

 time reading through the directions for carrying out an experi- 

 ment during his attendance at the laboratory, only to carry 

 them out like a cook following a recipe. A little previous 

 study, a preliminary lecture, and a little personal instruction, 

 is more desirable ; then the experiments will be carried out 

 intelligently, and without the necessity of elaborate descriptions 

 of the mode of procedure. 



One would like to have seen a more complete account of the 

 use of a cathetometer. of specific gravity measurements, and of 



thermometer corrections : points of which it is most desirable 



that a student who subsequently r(S<arches should have a 



practical knowledge. , _ „ 



A. C . K. 



ORNITHOLOGY. 



Britain's ISii-ils ttiid tlicir W'sts. By A. Lan'usboroi'gh 



Thomson-, with an introduction by J. Arthtr Thomson. 



340 pages. 132 plates. lOi-in. X 7' iii. 



iW. & R. Chambers. Limited. Price 21 ■ net.) 



This book, which is illustrated by Mr. Rankine's coloured 

 drawings, is a careful compilation of the most important and 

 interesting details with regard to British-breeding birds, in 

 which the writer has incorporated unpublished records of his 

 own and of many competent observers whom he counts amongst 

 his friends. The text is written in language which is easily 

 understood, and the system and nomenclature adopted are 

 those followed in the second edition of Howard Saunders' 

 " Manual of British Birds." 



.As regards the colouration of the birds and the eggs, the 

 plates will prove very useful. In some of them. hovve\er. one 

 particular flower, which is characteristic presumably of the 

 habitat of the bird, has been dragged into the picture and 

 emphasised in such a way that it detracts somewh.it from the 

 intention of the drawing. 



Professor Arthur Thomson contributes an introduction in 

 which he treats birds from a biological point of view, 

 emphasising the interest to be gained from their study, but 

 saying that while the living bird attracts most minds, and 

 provides a man with enough to kee|) him busy all his life, half 

 the wonder will be missed if there is not also some analysis of 

 structure. He touches on the behaviour, migration, .and 

 development and evolution, as well as the practical importance 

 of birds, and concludes with a plea for the efforts which are 

 beiu,g made towards bird protection, partly by legislation, 

 partly by the education of public opinion {e.g., as regards the 

 use of feathers in decoration, other than those from domesti- 

 cated birds, like the ostrich, and from birds shot for food) 

 and partly by the establishment of bird sanctuaries, some of 

 which have already been attended with remarkable success; 

 for when a bird has been exterminated, its loss is irreparable. 



W.M.W. 



NOTICES. 



A Ni:\V ITKLD GLASS.— We liave received from Messrs. 

 C. P. Goerz's Optical Works. Limited, a list of their Trieder 

 Binoculars, among which a new introduction, the- " Neo- 

 Trieder," calls for attention, as it has several special features, 

 among which are its excellent definition, its increased field of 

 view, which means, of course, that more of the field looked at 

 is seen, while there is enhanced stereoscopic effect and greater 

 illuminatiou and brightness of the picture consetpient upon the 

 emplo\-ment of larger object glasses. 



SCILXTIITC PHOTOGRAPHIC PLATES.— There nmst 

 be many who are seeking for photographic plates for various 

 scientific purposes, and to these we commend the descriptive 

 list of those issued by Messrs. Wratten and Wainwright. of 

 Croydon. A great deal of useful information is incorporated, 

 and reference is given to special booklet which this firm has 

 prepared, dealing- with particular scientific work. 



A CINEMATOGRAPHIC HANU-CAMERA. — The 

 .Aeroscope, of which details have reached us is practically 

 a hand-camera loaded with four hundred and fifty feet of film 

 and worked by means of a small air engine. It is brought out 

 by the .Aeroscope Company, IS. Charing Cross Road. W.C. 



PRESERVATION OF THE EVE-SIGHT.— The receipt 

 of a siuall booklet entitled " Eye-Sight Preserved." containing 

 many useful hints, reminds us that Mr. Aitchison, who is 

 responsible for it, is always ready to test eye-sight and give 

 ad\ ice without charging any fee. 



NEW .\PP.\ R.VTl'S. — .Among the new instruments which 

 Messrs. Zeiss have recently put upon the market are telescopic 

 spectacles which ha\e been introduced for the benefit of 

 per.sons suffering from extreme myopia. .Another is the 

 cardioid ultra-microscope, devised by Ilr. Siedentopf. which is 

 adapted for the examination of colloid solutions, diluted 

 precipitates, and the observation of micro-chemical and photo- 

 chemical reactions. We may mention also the new oral 

 illuminator for the use of dental surgeons and the new method 

 of illuminating operating theatres in hospitals with a search- 

 light and distributing mirrors. 



ASTRONOMICAL LECTURE.— Mr. Frank C. Dennett 

 informs us that he still has a few dates vacant for the 

 delivery of his lecture on " The Sun, its Structure and 

 Influence." illustrated by an unique set of lantern slides. Mr. 

 Dennett's address is 6, Eleanor Road. Hackney, N. 



THE BRITISH ASSOCIATION.— A preliminary pro- 

 gramme has been issued for this year's meeting of the 

 British Association, which, as .already announced, is to take 

 place at Portsmouth, on .August 30th and following days. 



The opening meeting will be held in the Town Hall 

 on Wednesday evening, .August 30th. when Sir William 

 Ramsav. K.C.B.. will assume the presidency and deliver his 

 inaugural address. In the same hall the first evening 

 discourse will be delivered on Friday evening. September 1st, 

 by Dr. Leonard Hill, on "The Physiology of Submarine 

 Work," and the second, on Monday evening, September 4th. 

 bv Professor A. C. Seward, on " Links with the past in the 

 P'lant World." 



