174 



NATURE 



[May 2, 19 1 8 



volume, with maps; "Examination Papers in Ele- 

 mentary Engineering," R. M. Milne; "Alcohol and 

 Life : A Manual of Scientific Temperance Teaching 

 for Schools,' J. A. Hunter, illustrated; "Essentials of 

 Practical Geography," B. C. Wallis (Practical Modern 

 Geographies); "A Geography of America," T. Alford 

 Smith (Practical Modern Geographies). 



OUR ASTRONOMICAL COLUMN. 

 Minor Planets. — Mr. H. E. Wood records a 

 number of minor planets on plates taken last year at 

 Johannesburg. They have been identified by M. Louis 

 Fabry (Marseilles Circular, No. 10). The most in- 

 teresting is 722 Frieda; this planet had not been 

 observed since its discovery in 191 1, so its recovery is 

 fortunate. The Astronomical Journal, No. 729, contains 

 elements of an unidentified planet discovered at 

 Washington by Mr. G. H. Peters last November. 

 It may be identical with 293 Brasilia, 1906 WF, or 

 191 1 LU. If new, he proposes the name Washing- 

 tonia. Prof. Barnard followed the Wolf planet DB 



It has 



until April 4, when its magnitude was 



been so well observed that it ought to be possible 



to secure its re-observation at the next perihelion in 



1922. 



The Cepheid Variable SU Cassiopei^.^ — Further 

 investigations of this interesting variable star have 

 been made by W. S. Adams and H. Shapley {Astro- 

 physical Journal, vol. xlvii., p. 46). Mr. Shapley had 

 already shown that the variation could not be inter- 

 preted as the result of the rotation of a simple ellip- 

 soidal body, and the conclusion that the star is a 

 Cepheid has been verified by the new spectroscopic 

 observations. The range of photographic magnitude, 

 according to Parkhurst, is from 6-52 to 699, and the 

 variations of radial velocity, —18 to +4 km., are 

 correspondingly small. A period of 1-9495 days satis- 

 fies both series of changes, and the epoch of maximum 

 negative velocity precedes the maximum of light by 

 0-05 day. The spectral type varies from A9 at maxi- 

 mum to F5 at minimum. Taking the visual magni- 

 tude as 6-23, as given by Boss, the spectroscopic 

 parallax is identical with that derived by Van Maanen, 

 namely, +0010" ±0003". 



New Double Stars.— Mr. R. G. Aitken's twentv- 

 fourth list, giving details of 100 new double stars, 

 appears as Lick Observatory Bulletin No. 306. This 

 observer's systematic survey of the sky was initiated 

 in 1899, and the present list brings his' total published 

 discoveries up to 3000, the region covered being from 

 the pole to declination 14° S., and to declination 22° S. 

 from I3h. to ih. right ascension. All the stars in- 

 cluded are under 5" in distance, and in the present list 

 nearly half are less than i" apart, while sixteen do not 

 exceed 0-3". The brightest star included is 41 Ophiu- 

 chi, the components of which are rated as magnitudes 

 4'6 and 7"6, the position angle and distance being 298° 

 and 0-52* respectively. 



Journal of the Chaldean Society.— We have 

 pleasure in directing attention to a small astronomical 

 magazine which is issued quarterly by the Chaldean 

 Society under the title of The Chaldean. The publi- 

 cation has now reached No. 10 of the first volume, 

 and _ while dealing with astronomy generally, its 

 special appeal appears to be to observers of meteors. 

 The recent issue includes an article on astronomical 

 photography, and several notes on meteors by Mr. 

 Denning and others. A feature of particular interest 

 is a facsimile of a page from the observation book of 

 the late Prof. A. S. Herschel, which furnishes a good 

 example of the metnod of recording meteors. Com- 

 munications should be addressed to the editor, Mr. J. 

 Hargreaves, Bennington, Stevenage, Herts. 

 NO. 2531, VOL. Id] 



! RECENT WORK IN MINERALOGY AND 

 I PETROLOGY. 



I A MINERAL variously labelled johannite and 

 ! -^^ uranopilite in collections has yielded to Messrs. 

 [ E. S. Larsen and G. V. Brown the composition 

 I RO.UO3.SO3.4H2O, where R = Cu,Fe,Naj (the Amer- 

 I ican Mineralogist, vol. ii., p. 78, 1917). The new 

 : species thus indicated is called gilpinite, from the 

 typical locality Gilpin Co., Colorado; but a Cornish 

 specimen, one of those styled uranopilite, proves to be 

 identical. The authors insist that optical tests under 

 I the microscope are characteristic, and that their appli- 

 cation shows that more than one-third of the hundred 

 specimens of "secondary uranium minerals" examined 

 from various museums are incorrectly labelled. 



Mr. A. E. V. Zealley, in "Notes on Newly Recorded 

 Rhodesian Minerals" (Proc. Rhodesia Sci. Assoc, vol. 

 xvi., p. 17, 1917), includes an account of the stann- 

 iferous tantalite of the Victoria tinfield, discovered in 

 1911, but not hitherto described. Two other Rhodesian 

 occurrences of tantalite are noticed. 



Messrs. R. C.^ Wells and B. S. Butler describe 

 (Journ. Washington Acad. Sci., vol. vii., p. 596, 1917) 

 a mineral sulphide of tungsten, under the name of 

 tungstenite. The composition is probably WS^, and 

 the specific gravity is near 74. It looks like graphite, 

 and has a hardness of only 25. This mineral occurs 

 in some abundance in a vein with galena, pyrite, tetra- 

 hedrite, and argentite. in Salt Lake Co., Utah. 



The view advanced by Mr. J. B. Scrivenor in 

 19 10-14 as to the age of the detrital tin deposits of 

 the Kinta district, Perak (see Nature, vol. xciv., 

 p. 348), has now been disputed in a detailed paper by. 

 Dr. W. R. Jones (Quart. Journ. Geol. Soc, vol. Ixxii., 

 p. 165, 1917). Mr. Scrivenor urged that these bouldery 

 deposits were derived from the surface of Gondwana- 

 land during the Permian ice-age, which is responsible 

 for the Talchir Beds of India. Dr. Jones, however, 

 connects the tin ore with the Mesozoic granite now in 

 situ in the district, and he brings forward strong 

 evidence to show that there is only one alluvial tin- 

 bearing series in Kinta, instead of two, superposed on 

 one another, and separated by a long geological in- 

 terval. 



Those acquainted with the work of Mr. W. H. Good- 

 child on the Insizwa Range in the Cape Province (Inst.of 

 Mining and Metallurgy, Bull. 147, 1916) will welcome 

 the publication of Dr. Du Toit's researches in the 

 area, extending from 1903 to 1912 (Du Toit and 

 Rogers, "The Geology of Part of the Transkei," South 

 Africa Geological Survey, Explanation of Sheet 27, 

 1917). The geological map, showing a magnificent 

 series of dolerite sills, penetrating the Karroo strata 

 up to the highest Stormberg beds, is now also issued, 

 on a scale of i : 247600. The Insizwa gabbro, with 

 its copper ores bearing nickel and platinum, is included 

 in the north-east of the sheet, and the memoir con- 

 tains a map showing the whole of the gabbro-norite 

 masses. The three sulphides — chalcopyrite, pent- 

 landite, and pyrrhotine — have separated from the 

 igneous rock in the order in which they are here 

 named, as a gravitative differentiation-product in the 

 concave floor of a great sill. Forty-five miles of visible 

 contact along the base of this sill await systematic 

 exploration. The occurrence is discussed, in compari- 

 son with that at Sudbury, in the recently issued report 

 of the Ontario Nickel Commission. 



Prof. R. A. Daly (" Low-temperature Formation of 



Alkaline Felspars in Limestone," Proc. Nat. Acad. Sci., 



I vol. iii., p. 659, 1917) describes a dolomite from Water- 



I ton Lake, on the Montana and Alberta border, which 



j contains 34-5 per cent, by weight of orthoclase and 



