158 



NATURE 



[June i8, 1896 



Several parts of the very fine " Illustrations of the Zoology of 

 li. M. Indian Marine Surveying Steamer Investigator" under 

 the Commander, A. Carpenter, the late Commander, R. F. 

 Iloskyn, and Commander C. F. Oldham, have lately been 

 received. The plates are splendid examples of photo-etchings, 

 and they will be treasured by marine zoologists. Fishes are 

 represented upon sixteen plates, Crustacea upon fifteen plates, 

 and Echinoderma upon five plates. The illustrations are only 

 accompanied by brief explanations, the descriptions of the 

 various species having appeared in the Annals and Magazine of 

 Natural History, and in the Journal of the Asiatic Society of 

 Bengal. Mr. A. Alcock is responsilile for the fishes described 

 and figured, and, in conjunction with Mr. A. R. S. Anderson, 

 for the Echinoderma. The Crustacea have been mostly done 

 under the direction of the late Mr. J. Wood-Mason. 



Nearly a year ago (Nature, vol. Hi. p. 290), the second volume 

 of the .second edition of Dr. George Lunge's treatise on "The 

 Manufacture of Sulphuric Acid and Alkali " (Gurney and Jackson) 

 was reviewed in these columns, and the value of the work to in- 

 vestigators and industrial chemists as a standard work of reference 

 on alkali manufacture was pointed out. The third volume, com- 

 pleting the second edition of the book, has now been published, 

 and the words of praise applied to the second volume are just as 

 fully deserved by the present one. The amplification of the 

 original text has been so considerable, and the revision so 

 thorough, that the work has grown beyond recognition. Only 

 a few chapters resemble those of the first edition, and the chap- 

 ters on ammonia-soda, on the more recent soda-process, on the 

 Deacon process, and the other chlorine processes, have been 

 entirely rewritten ; while a section on the preparation of alkalis, 

 chlorine, and chlorates by electrolysis, appears for the first time. 

 The second edition of the complete work is half as large again as 

 the first ; it is well up to date, and forms a most serviceable 

 survey and digest of the whole ground of alkali manufacture. 



The meteorological and magnetic observatory of the Uni- 

 versity of Odessa has for its functions not only the reading of 

 the numerous instruments with which it is equipped, and the 

 discussion of the results observed and registered, but it is 

 intended also to serve as a high school where students of the 

 faculty of physics and mathematics can be trained in the work of 

 meteorology and physical geography. In order to give more im- 

 portance to this course. Prof. Klossovsky has drawn up a syllabus, 

 which is printed in the 1895 volume of the " Annales" of the 

 Observatory at Odessa. The course is divided into three parts, 

 the first two of which are devoted to fundamental observations, 

 to the installation and study of instruments used in meteorology 

 and terrestrial physics, and to the determination of various 

 elements. The third course is intended for those who propose to 

 take up physical geography or meteorology as a special subject. 

 The programme is an admirable outline of the work of meteoro- 

 logy and terrestrial physics, and but for limit of space we would 

 give a full translation of it. Schools in meteorology are so few, 

 that the development of the curriculum of the Imperial Uni- 

 versity at Odessa will be welcomed by all who think that trained 

 investigators and experimental work are needed for the advance- 

 ment of the science. 



The additions to the Zoological Society's Gardens during the 

 past week include a Hoolock Gibbon [Hylobates hoolock, ? ) from 

 Assam, presented by Mrs. Firman ; two Fat Dormice {Myoxiis 

 glis) from Austria, presented by Mr. John G. Haggard; a Short- 

 toed Eagle {Circcctiis gallicus) from Egypt, presented by Dixon 

 Bey ; a Vulturine Eagle (A,;iiila vcrreauxi) from South Africa, 

 presented by Mr. J. Clark; two Short-eared Owls [Asio 

 brachyotns) from Ireland, presented by Captain R. A. Ogilby ; 

 five Cormorants {Phalacrocorax carho) from the Isle of Mull, 

 presented by Maclaine of Lochbuie : three Dwarf Chameleons 

 NO. 1390, VOL. 54] 



(Channcleon fiuiniliis) from South Africa, presented by Miss Jessie 

 M. Hudson ; eight Natterjack Toads {Biifo calamita), two 

 Common Toads (Biifo vulgaris), British, presented by Mr. 

 Stanley S. Flower ; two Axolotls {Sirecion mexicatiiis) from 

 Mexico, presented by Mr. W. Temple ; nine Green Turtles 

 {Clulone viridis) from .\scension, presented by Mr. J. C. 

 Adlam ; a Hoolock Gibbon {Hylobates hoolock, 9 ) froin Assam, 

 an Indian Chevrotain {Tragiiliis meininna), two Indian Drongos 

 [Chibia holtentota), two Tigers (Felis tigris, S 9 ) from India, a 

 Javan Chevrotain (Traguius Javanica) from Java, a Harnessed 

 Antelope {Tra^elaphtis scriptiis, i )from West Africa, deposited. 



OUR ASTRONOMICAL COLUMN. 



PHOTOGRArHS OF STELLAR SPECTRA.— Dr. F. McClean is 

 now engaged on a photographic investigation of the spectra of the 

 northern stars down to the third magnitude. About 160 stars 

 will thus be included in the survey. .Some of the results, which 

 have been recently communicated to the Royal Astronomical 

 Society, comprise the spectra of twenty-three characteristic 

 helium stars, and photographs of the spectra of six stars of the 

 third magnitude showing the transitions from one type to 

 another [Alonth/y Notices, vol. Ivi. p. 428). The instrument 

 used is a photographic telescope of 12 inches aperture and 11 

 feet 3 inches focal length, having an objective prism of the same 

 aperture placed in front of the object-glass. The refracting angle 

 of the prism is 20°. The prism is mounted on a hinged frame, 

 and the cell containing it can be rotated within the frame, so that 

 all necessary adjustments can be effected with facility. 



The Natal Ouservatory. — Two reports which have 

 recently been received from Mr. Nevill, the Superintendent of 

 the Natal Observatory, indicate considerable astronomical 

 activity at this southern station. "The principal series ot 

 observations in progress is the comparison of the declination 

 deduced from observations made at the observatories in the 

 northern and southern hemispheres by a comparison by Talcott's 

 method of the zenith distance of northern zenith stars and 

 southern circumpolar stars at upper and lower culminations." 

 Over a hundred pairs of stars are under observation. The 

 publication of the Greenwich observations of Mars during the 

 opposition of 1892 renders it possible to utilise the corresponding 

 Natal observations for the determination of a new value of the 

 solar parallax, and this work will be undertaken. During the 

 opposition of Mars in 1894 the weather proved very unfavour- 

 able, and no observations of value were secured. A great mass 

 of important work done at the observatory awaits facilities for 

 publication. The entire staff amounts to only four observers 

 and computers, and the instrumental equipment is equally small. 

 The system of time signals and meteorological work were carried 

 on as in former years. 



Possible Changes in the Earth's Rotation.— -■Xs the 

 result of a recent investigation (Comptcs rendiis, June i). Prof. 

 Newcomb makes the startling suggestion that the earths rota- 

 tion is not perfectly uniform. The discussion was undertaken 

 in connection with the long-period inequalities in the moon's 

 mean motion,iwhich so far have not been satisfactorily explained. 

 The possibility of a variation in the earth's rotation period being 

 admitted, and consequently of an error in our mode of reckoning 

 time, it becomes necessary to employ some method of measuring 

 time which shall be independent of the earth's rotation. This 

 appears to be best furnished by observations of the transit ot 

 Mercury. Prof Newcomb has accordingly discussed all the 

 November transits since 1677, and has compared the observed 

 times of ingress and egress with those computed on the basis ot 

 his new tables for the sun and Mercury. .Although in many- 

 cases the residuals may not be greater than the probable errors, 

 there is a significant systematic character about them, as shown 

 when the observations are grouped as follows :— 



Residuals. 

 Transits. s. s. 



1677— 1769 -54 ± 2-5 



1789— 1861 -f6-4 ± 1-5 



1868 -1-5 ±3-5 



1881 — 1S94 -3-1 ± 1-6 



It is concluded that " the observations of transits of Mercury 

 clearly indicate small variations in the rotation of the earth, of 



