258 



NA TURE 



[July 14, 1898 



We have received from Messrs. H. W. Cox, Ltd. , their price 

 list of induction coils and apparatus for producing X-rays. In 

 it is to be found full particulars as to the prices and capabilities 

 of the specialities of this firm. 



The current number of the Journal of the Society of Arts 

 contains the first of the series of Cantor lectures, by Prof. Noel 

 Hartley, F.R.S., on " The Thermo-Chemistry of the Bessemer 

 Process. " 



The additions to the Zoological Society's Gardens during the 

 past week include two Vervet Monkeys (Cercopilkecus lalandii) 

 from Natal, presented by Mr. W. Champion ; a Great Wallaroo 

 {Macropus robustus) from South Australia, presented by Miss 



W. Jackson ; two Hedgehogs {Erinaceus, sp. inc. ) from 



North Africa, presented by Sir Harry Johnston, K.C.B. ; a 

 European Pond Tortoise {Emys orbiadaria), European, pre- 

 sented by Mr. A. H. Cocks ; an Algerian Tortoise ( Testudo 

 iberd) from Algeria, presented by Mr. G. H. Gude ; a 

 Sulphurous Snake {Phrynonax sulphureus), a Deadly Snake 

 {Lachesis atrox), a Centipede from Trinidad, presented by Mr. 

 R. R. Mole ; a Lataste's Viper ( Vipera litasti) from Alg eria, 

 presented by Mr. Carl Hagenbeck ; two Yellowish Finches 

 {Sycalis luteold) from Brazil, presented by Mr. F. L'hoest ; an 

 Arabian Baboon {Cynocephalus hamadryas) from North Africa, 

 a Grey Parrot {Psittacus erithaciis) from West Africa, a 

 Swainson's 'Loxik&Qt {Trichoglossus twvcz-hollandu^), two Pen- 

 nant's Parrakeets (Platycercus elegans) from Australia, a Thick- 

 necked Tree Boa {Epicrates cenckris), a Corais Snake (Coluber 

 corais) from Trinidad, deposited ; a Giraffe {Giraffa camelo- 

 pardalis, i ) from Senegal, eight Lateral White-eyes {Zosterops 

 lateralis) from New Zealand, two Indian Tantalus {Pseudo- 

 tantahis leucocephalus) from India, two Spotted Pigeons 

 [Columba maculosa), a Burmeister's Cariama {Chunga bur- 

 meisteri) from Argentina, four Wandering Tree Ducks {Dendro- 

 cygna arcuata) from the East Indies, purchased ; a Puma {Felis 

 concolor), two Barbary Wild Sheep (Oz^w iragelaphus), a Bu rrhel 

 Wild Sheep (Ovis burrkel), born in the Gardens. 



OL/R ASTRONOMICAL COLUMN. 



COMETAKY News. — In the Astronomische Nachrichten (Nos. 

 3501 and 3504) we find the ephemeris for both of Perrine's 

 comets, namely March 19 and June 14. The former, which is 

 situated in the northern part of Auriga and is visible tor the 

 greater part of the night, is gradually receding from the earth 

 and becoming faint. Its ephemeris for the present week is : — 



1898. R.A. 



h. m. s. 



July 16 ... 5 28 46 



17 ... 30 46 



18 32 44 



19 ... 34 40 



20 ... 36 33 



21 ... 5 38 25 



\2h. Paris M.T. 



Decl. 



o-o8 



+ 53 48 47 



44 17 



39 48 



35 21 



30 55 

 + 53 26 32 ... o-o8 



Perrine's comet, discovered on June 14, is, however, rapidly 



increasing in brightness and is getting near the sun, rendering 



observation somewhat difficult towards the end of this month. 



Its ephemeris for the week, as calculated by Dr. Berberich, is— 



\zh. Berlin M.T. 



1898. R.A. (app.) Decl. (app.) Br. 



h. m. s. 



July 14 ... 6 8 45 .. +4°4 387 ... 2-98 



15 ••• 13 7 •• 43 527 



16 ... 17 25 ... 43 56 



17 ••• 21 40 ... 42 17-3 ... 3-36 



18 ... 25 52 ... 41 27-8 



19 ••■ 30 o ... 40 371 



20 ... 34 5 ••• 39 45-4 



21 .. 6 38 7 ... +38 52-3 ... 3-96 



NO. 1498, VOL. 58] 



Wolf's comet, which is situated in Taurus, is gradually 

 increasing in brightness and moving eastwards. This body will 

 approach Mars very closely on July 19, their positions differing 

 in R.A. and Declination by only I'gm. and o'"0 respectively, as 

 computed by Herr Thraen. Its ephemeris is as follows : — 



Decl. 



Br. 



19 51*8 ... 2*2 

 485 

 44-8 



40*9 ... 2 '2 

 366 



32-1 



27-5 



-H9 227 ... 2*3 



Comet Criacobini, though moving rapidly northwards as 

 regards declination, is becoming now a faint object, being one- 

 half the brightness it was at the lime of its discovery. 



Stars havi.ng Peculiar Spectra. — In a recent Harvard 

 College Circular (No. 32) Prof. Pickering publishes a list of 

 stars the spectra of which are described as peculiar. Most of 

 these have great southern declinations, so we give below a 

 short list of the few that can be observed in these latitudes. 

 The stars were all discovered by Mrs. Fleming in her regular 

 examination of the Draper Memorial photographs. 



Two other stars with great southerly declinations, A.G.C. 

 14145 and 14686, show spectra with bright and dark hydrogen 

 lines. In the former H3 and H7 are variable. On June 2, 1893, 

 they were bright and superposed on a broad dark band. On 

 April 17, 1895, and March 17, 1896, these lines, like the other 

 hydrogen lines, were dark. In the latter star the hydrogen 

 lines were also variable. On May 20, 1892, HS, H-y and H5 

 were dark. On April 3, 1895, Hj8 was bright, and on April 21, 

 1895, H;3 and H7 were bright. H^ and H^ were dark with 

 the edge of greater wave-length apparently bright. 



A careful study of the spectra of some of the bright southern 

 stars has enabled Miss Cannon to increase the number of 

 stars containing the additional hydrogen lines first seen in j* 

 Puppis. Thus in A.G.C. 17572, 3925, 4027, 4202 and 4544 

 are present and dark. In A.G.C. 8631 and 22763 the lines 

 4027, 4202 and 4544, and the bands 4633 and 4688 are present 

 and bright. In the stars A.G.C. 10863, 22748 and 22843, the 

 hydrogen lines 3925, 4027, 4202 and 4544 are present and dark, 

 and the bands 4633 and 4688 are bright. In the last two men- 

 tioned stars, and also in A.G.C. 931 1, 26 Canis Majoris, the 

 band 4633 is described as being double. 



The Constant of Aberration and Stellar Mag- 

 nitudes.— In determining the constant of aberration by stars 

 of different magnitudes, using the well-known method of Talcott, 

 Prof Doberck finds (^j/r. Nachr., 3504) that the values decrease 

 as the magnitudes decrease. Thus, using stars averaging 4*4 in 

 magnitude, the value of the constant he obtained was 20" '639 ± 

 o""075, with stars averaging 5-4 it was 20" -430 + o"'o63, and 

 with those of 6 '4 magnitude the value was 20" "385 + o"'o66. 

 Prof Doberck suggests that perhaps this fact may explain diflfer- 

 ences in the values obtained at different observatories, such 

 differences being always in excess of their probable errors. 



The Eclipsed and Un-eclipsed Sun.— In the Bulletin 

 de la Societi? Astronomique de France (for July), M. Deslandres 

 gives an account of the methods he adopts in photographing 

 the entire chromosphere of the sun. As this beautiful method 

 has been previously published, we need only draw attention to 

 the very fine phototypes which illustrate the magnificent 

 results that he has so successfully obtained. Knowledge for the 

 same month contains two reproductions from Prof. Campbell's 

 negatives of the solar corona obtained in India this year. 



