KXOWLIiDGi:. 



Df.cf.mber, 1912. 



world. The only tiis;iii\aiitages are thai ihc islands 

 lit- ninety miles from the mainland : that there is no 

 mail communication with them, and they are unin- 

 habited. Dr. Jameson wonders why Saville-Kent 

 wanted to grow pearl-shells at the Abrolhos, far 

 south of their natural habitat. I can tell him ! 

 Kent found that there was a warm water current, 

 and conceived the idea that pearl-shells might do 

 there. He obtained concession rights there and 

 tried to Ho' ;-, company in London for /l 00,000, 



and induced me to put my name to it. After a 

 week's reflection, however, I withdrew my name, as 

 the closer I studied it the less I liked it — and the 

 Company was never formed. The project could 

 have been worked very comfortably from the town 

 of Geraldton, not far distant ; but the want of 

 sheltered waters and of any large extent of mud 

 bottom to afford a large food supply was alone 

 sufficient to deter a prudent man from encouraging 

 the idea. 



REVIEWS. 



rHOTOGK.APHY. 

 Tclcphotoiiraphy. — By CvRll. F. Lan-Davis, F.R.P.S. 

 127 pages. 16 full-page plates and 7 diagrams. 7}-ins. X5i-ins. 

 (George Roiitledge & Sons. Price 2 ■ net.) 

 The author of this book has produced a useful and 

 interesting little volume dealing with the subject of Tele- 

 photography, and one which should be extremely valuable 

 to the practical worker. The work not only deals with 

 the subject in its relation to distant objects, but explains 

 in an equally clear manner its value in photographing near 

 ones, an important application frequently lost sight of. In 

 explaining the advantages of the Telephoto system for distant 

 objects, comparison is drawn between the size of the images 

 given by a five-inch and twenty-inch focus lens respectively, 

 and then it is shown how by the use of a Telephoto combination 

 consisting of a five-inch positive and a two and a half-inch 

 focus negative lens, and seven and a half inches of camera 

 extension, the size of the image would be the same as that 

 given by a twenty-inch focus lens and re<|uiring practically 

 that extension of camera. The Telephoto lens thus places 

 the means at our disposal of obtaining large pictures with 

 only small extension of camera. In discussing the use of 

 these lenses for near objects, the author gives an example 

 in which the camera extension is only a little more than half 

 that required by an ordinary lens for the same size of image, 

 with the object several feet further oiT, thus giving improved 

 perspective. Examples are also given of rapid Telephoto 

 lenses which are mostly of fixed focus, and so only give one 

 degree of magnification for distant objects. The large Adon 

 manufactured by Messrs. J. D. Dallmeyer is of this type and 

 works at from F. 4-5, F. 6 to F. 10, and is supplied in focal 

 lengths suitable for obtaining pictures of from two to four 

 times the usual size, and can be employed on reflex cameras 

 where the image is focused up to the moment of the 



exposure. Some interesting remarks are also made regarding 

 the exposure re(|uired for distant objects. Theoretically, this 

 should be proportional to the square of the magnification, but 

 practice has shown that it is better to take one-half of this 

 when working without a screen, and only give the full time 

 when using a properly-adjusted light filter. The book, which 

 is clearly written, contains numerous examples illustrating the 

 various applications of Telephotography, as well as carefully 

 compiled working data, and should certainly be studied by all 

 those interested in this branch of photographic work. 



F.S. 



ZOOLOGY. 



many text figures. 9-in. X 6-in. 



(Methuen & Co. Price 10/6 net.) 



This volume is a companion one to a History of Hirds 

 written by Mr. W. P. Pycraft, the general editor of the series, 

 but as it deals with Reptiles, Amphibians, and lower Chordata; 

 it is the joint work of several well-known naturalists and it has 

 been edited by Mr. J. T. Cunningham. The volume is by no 

 means an ordinary text book and it deals with Natural History 

 in a general sense rather than with classification. We find 

 discussed in detail, adaptations, coloration and its interpreta- 

 tion, life-histories and modes of reproduction. The considera- 

 tion of reptiles gives an opportunity of tracing their pedigrees 

 and relationship. Under the heading of Fishes, the phenomena 

 of sex are dealt with, as well as the production of sound, light 

 and electricity. In every way this is a modern book, written, 

 produced and illustrated in a modern way. 



W". M. W. 



NOTICES. 



CORRPXTIONS.— Mr. Henry Faulds points out that 

 there is a mis-spelling on page 440, namely " Hari-kari." for 

 the Japanese " Hara-kiri." He believes that the first form 

 has got into some dictionaries, but it is absolutely wrong. 



In Mr. Redgrove"s review of Dr. Dakin's book, an addition 

 made by him on his proof was inserted at the wrong point. 

 In the sixth line from the bottom of the review on page 442. for 

 "in the bodv " read "when perfused through a surviving 

 liver " and next line for " when perfused through a surviving 

 liver " read " is produced." 



MR. LFIT/ HONOURED.— Recently the Faculty of 

 Medicine of the University of Giessin conferred the honorary 

 degree of Doctor of Medicine upon Frnst Leitz. Junior, the 

 junior partner of the celebrated optical firm of E. Leitz, of 

 Wetzlar, and KS, Bloomsbury Square, London. 



It is only a little tirore than a year since the University of 

 Marburg honoured the senior partner of the same firm by 

 conferring upon him the degree of Doctor of Philosophy. 



We congratulate Messrs. Leitz on the fact that their services 

 lo Science have been so properly and suitably recognised. 



MR. HDWARl) BAKER'S CATALOGUE.— We have 

 received the thre'i-hnndred and fourth catalogue of more than 

 one thousand books on sale at Edward Baker's Great Book- 

 Shop. Birmingham. Among them are many first editions, 

 limited issues, and presentation copies, as well as a number of 

 American Transactions. 



THE " LONDON " MICROSCOPE.— Our readers will be 

 interested to hear that Messrs. R. & J. Beck, Ltd.. have pro- 

 duced a new microscope. .'V special feature of it is the large 

 and heavy base, which ensures perfect rigidity when it is in a 

 horizontal as well as in a vertical position. There is a 

 specially smooth-working and reliable fine adjustment, while 

 the stage is four inches square, and the instrument is finished 

 in Messrs. Beck's special black enamel which withstands the 

 actions of acids and spirit. 



BOTANICAL WORKS.— Weare pleased to draw attention 

 to Messrs. John Wheldon & Co's. handily arranged catalogue 

 of botanical books. The contents are arranged under three 

 main headings : Economic. Geographical, and General. Each 

 of these is again sub-divided so that the list referring to any 

 particular branch of botanical science can easily be consulted. 



