142 



KNOWLEDGE. 



[June 1, 1897. 



subjects covering a wide range, to wit — an Australian family party ; 

 a farm in the Philippines ; Polynesian weapons and costume, etc., etc. ; 

 and hundreds of illustrations, depicting all phases of human life, 

 adorn the text. 



Sonfgen Sails. By Edward P. Thompson. (D. ran Nostrand, 

 New York.) 7s. 6d. We have here a most exhaustive summary of 

 the practical applications of the so-called X rays, together with the 

 facts and principles relating to the phenomena occurring between and 

 around charged electrodes separated by different easeous media at 

 various pressures. A valuable feature of the work consists in the 

 numbering of the paragraphs which contain cross-references to other 

 parts of the book where kindred phenomena are described, thus 

 facilitating analogy, contrast, and suggestireness. A fine portrait of 

 Dr. Rontgen forms the frontispiece, and there are sixty diagrams and 

 forty-five half-tone illustrations in the text, all of the best. A chapter 

 on "Theoretical Considerations" is contributed by Prof. Anthony. 

 The large number of references to periodical literature greatly 

 enhance the value of Mr. Thompson's book. 



J^xterior ami Interior Fhotoriraphy. By F. W. Stills, F.R.M.S. 

 Those who have mastered the preliminaries of photography — hav.:', in 

 fact, soared above the snap-shot stage— will find this little book very 

 useful. It deals with the science of the effects of light on the 

 plate and on the eye, and the manipulation of the camera in taking 

 artistic portraits or interiors. It teaches how to finish a photo- 

 graph, and many useful hints and reliable formulse are given. 



Everybody's Guide to Fhoioyraphy. By "Operator." This is a 

 thoroughly up-to-date and practical little book. It is very com- 

 prehensive, including even an explanation of the nature of the X 

 rays, and should be found of great service to a practical photo- 

 grapher. The miscellaneous information given is decidediv above 

 the average of photographic guide books, and a great number of 

 pitfalls to which the amateur is inclined to fall an easy prey are 

 shown up, and may be avoided by a careful jierusal of this guide. 



Celesiial Muttons : a Handy Booh on Astronomy. Ninth Edition. 

 Semarkable Comets. Fifth Kdition. Stmarialile Eclipses. Second 

 Edition. By W. T. Lynu, B.A., F.R.A.S. We have pleasure in 

 noting new editions, carefully revised and brought up to date, of the 

 three handy little reference books with which Mv. Lynn's name is so 

 intimately associated. Mr. Lynn's well-known care and exactness, 

 combined with a clear and concise style, fully account for the 

 popularity evidenced iu the case of the "' Celestial Motions " by the 

 appearance of nine editions in less than fourteen years. 



Mr. Henry Frowde announces that a work of considerable interest 

 to practical astronomers is in the press, viz. : " Tables for Facilitating 

 the Computation of Star-Constants." By E. J. Stone, M.A , F.R.S., 

 formerly Her JIajesly's Astronomer at the Cape of Good Hope, and, 

 later, Radcliffe Observer at Oxford. Modified and Revised by H. H. 

 Tiu'ner, M.A. , B.Sc., SavUian Professor of Astronomy in the Universitv 

 of Oxford. — Mr. Turner claims that his revision will effect an appre- 

 ciable saving of time. 



I » I 



BOOKS RECEIVED. 



Sirds of our Islands. By F. A. Fulcher. (Melrose.) Illustrated. 

 3s. 6d. 



A Treatise on Hocks, Sock-weathering, and Soils. By George P. 

 Merrill. (Macmillan.) Illustrated. 17s. net. 



T/ie Sfori/ of the Mine. By Charles Howard Shinn. (Gay & 

 Bird.) Illustrated. 6s. 



A Secalculalion of tlie Atomic WeiqTits. By Frank Wigglesworth 

 Clarke. (Smithsonian Institute, Washington.) 



Citii and Guilds of London Institute- Seport of the Governors, 

 March, 1897. ■ 



Seport of the Directors of the Liverpool Observatory, 1896. 



Is the Earth a Planet ? By C. Robertson. (Elliot Stock.) 2s. 



First Stage Physiography. By A. M. Davies, B.Sc. (Clive.) 

 Illustrated. 2s. 



Genesis and Matrix of the Diamond. By the late Henry CarviU 

 Lewis, M.A. Edited by Prof. Bonney, LL.D., F.R.S., from Unpub- 

 lished Manuscripts. (Lcngmans.) Illustrated. 7s. 6d. 



The Saturalist's Directory, 1897. (L. Upcolt Gill.) Is. 



The Story of the Earth's Atmosphere. By Douglas Archibald, 

 M.A. (Newnes.) Illustrated. Is. 



A Handbook of the Birds of Great Britain. Naturalist's Library. 

 Edited by E. Bowdler Sharp. (Allen & Co.) Illustrated. 6s. 



Problems of Xature. By Gustav Jaogar, M.D. Translated and 

 Edited by Dr. Schlichter. (WiUiams & Norgate.) 



Wild Noricay. By Abel Chapman. (Arnold.) Illustrated. ICs. 



English Literature. By Stopford A. Brooke, M.A. Literature 

 Primers. (Macmillan & Co.) 



The Months. By Leigh Hunt. With Biographical Introduction 

 by William Andrews, F.fi.H.S. (Loudon : Andrews k Co.) 2s. 



Fortnightlii Eevietc — Mai/. (Chapman & Hall.) 2i. 6d. 



The Elements of Physics! By E. L. XichoUs and W. S. Franklin. 

 Vol. III. — Light and Sound. (Macmillan.) Illustrated. 6s. net. 



Results of Sain, Sirer, and Evaporation Observations. With 

 Maps and Diagrams. By H, C. Russell, F R.S., Government 

 Observatory, New South Wales. 



The T'e'rtebrate Skeleton. By Sidney H. Reynolds, M A. 

 (University Press.) Illustrated. 12s. 6d. 



First Stage Mechanics of Fluids. By G. H. Bryan, D Sc, and 

 F. Rosenberg, M.A. (Clive".) Illustrated. 2s. 



Tlie Year Book of Photography and Amateurs' Guide, 1897. 

 {Photographic News Office.) Illustrated. Is. net. 



The Birds of our Countrq. By H. E. Stewart, B.A. (Digby, Long, 

 & Co.) Illustrated. 3s. 6d. 



Heart Disease and the Nanheim Treatment. By Joseph Kidd, 

 M.D. (Hodder & Stoughton.)' Is. 



Beetle Collectors' Handbook. By Dr. E. Hofmann. (Sonnenschein.) 

 Coloured Plates. 4s. 6d. 



ARISTARCHUS AND THE SINUS IRIDUM. 



By E. W.\LTER Maunder, F.E.A.S. 



TWO great observatories are at the present time 

 engaged in the work of publishing photographic 

 atlases of the moon. Such a publication has 

 been mooted from the very earliest days of 

 astronomical photography, but its actual accom- 

 plishment has for years past seemed in danger of indefinite 

 postponement. It is therefore cause for especial con- 

 gratulation that not one such atlas, but two, are already in 

 progress of publication, whilst a third is promised. 



The first atlas is being produced from the negatives 

 secured by MM. Loewy and Paiseux with the great 

 equatorial coude of the Paris Observatory. The original 

 negatives were some six and a half inches in diameter, 

 and have lieen subsequently enlarged in the camera 

 fourteen or fifteen times, and have been reproduced in 

 heliogravure by M. Fillon. They are therefore on the 

 superb scale of about eight feet to the lunar diameter. 

 The quality of the reproductions is of the highest order, 

 and being in heliogravure they are permanent, and only 

 less faithful than would be positives on glass. The 

 character of the pictures is one of vivid contrast and bold 

 relief. 



The second atlas comes from the Lick Observatory, and 

 consists of enlargements from negatives of the moon taken 

 in the focal plane of the great thirty-six-inch refractor of 

 that observatory, but with the aperture considerably 

 reduced. The atlas is being prepared and published at 

 the cost of Mr. W. W. Law, of New York City, and is 

 intended when complete to consist of at least sixty plates 

 with index map. The scale of reproduction is considerably 

 smaller than that of the Paris atlas — the magnification 

 being only about seven diameters. The resulting chart is 

 to be on the same scale as the classic maps of Beer and 

 Miidler — 38-3(5 inches to the lunar diameter. The chief 

 object of the reproduction has been to bring out detail 

 rather than to exhibit contrast. The Lick photographs 

 are therefore less striking as pictures than those of the 

 Paris atlas, but possess some advantage over it. The two 

 will be largely supplemental of each other, and together 

 will supply a record of the lunar surface far surpassing in 

 accuracy and value anything which we have hitherto 

 possessed. 



The accompanying plate is a reproduction, on a reduced 

 scale (two feet to the lunar diameter — that is to say, on 

 the same scale as is represented in the maps of Nelson's 

 moon), of the fifth photograph in the Lick series. The 

 reduction was necessary in order to get the entire 

 picture into the page of Knowledge, but has rendered 

 unavoidable some loss of distinctness of detail. It repre- 



