March 24, 1881] 



NA TURE 



49; 



deposit, we must take into account not only its purity, but also 

 the size of the diatomacex it contains ; thus, M. Gobi recom- 

 mends especially those deposits which contain mostly frustales 

 from the species of Epithcmia, Navicula, Syiicdra, and Mdosira, 

 their frustules being of a greater size and more porous than 

 those of the Fragitlaria, Couoneis, Nitzsc/iia, &c. As to the 

 use of pounded coal or bricks, and of sand, it ought to be quite 

 given up. 



At the Annual Meeting of the Davenport (U.S.) Academy of 

 Sciences on January 6 a very satisfactory report was given of the 

 condition of the Society and of the good work it is doing. The 

 president gave an address, in which he sketched the progress 

 which has been made in a knowledge of the Mound Builders, 

 the prehistoric people of the Mississippi Valley, to whose 

 remains the Academy has all along devoted special attention. 



A SMALL well-printed in memoriam volume on the late Prof. 

 Benjamin Peirce has been issued at Cambridge, Mass. It con- 

 sists of the various notices, poems, addresses, &c., that appeared 

 in consequence of^his death, including three funeral sermons. 



The third Annual Report of the Dulwich College Science 

 Society speaks hopefully of its condition. The Society has been 

 steadily progressing, and has already collected a museum ' ' which 

 would do credit to many an older society." The Report contains 

 abstracts of several of the papers and lectures given during the 

 year. 



An encouraging Annual Report (the forty-seventh) has been 

 sent us from the \ork School Natur.il History Society ; all its 

 sections have evidently been doing well. In connection with 

 tliis we are glad to notice that, under the title of the Natural 

 History Journal and Sclwol Reporter, the journal conducted by 

 the Societies in Friends' Schools has assumed a new and more 

 attractive form, at the same time that its programme has been 

 somewhat extended. The two numbers for February and March 

 contain some creditable original papers. 



A SECOND edition of Mr. W. C. Wyckoff's "Silk Goods of 

 North America " has been publishedj; the first edition «as 

 noticed in Nature, vol. xx. p. 574. 



The additions to the Zoological Society's Gardens during the 

 past week include a White-fronted Capuchin f^Cebus albifrons) 

 from South America, presented by Mr. C. Drake Sewell ; a 

 Ring-tailed Coati {Nasua rtifa) from South America, presented 

 by Mrs. Fuller; a Common Badger (Meles taxia), British, pre- 

 sented by Mr. Rocke ; a Black-winged Peafowl (Pavo tiij^ri. 

 pcnnis) from Cochin China, presented by Mr. J. Marshall ; a 

 Rough-eyed Cayman (Alligator sclerops) from South America, 

 presented by Mr. Arthur C. Ponsonby ; a Horrid Rattlesnake 

 {Crotalus horridus) from Brazil, presented by Mr. C. A. Craven; 

 a Jararaca ( Trigonocep/ialia atrox) from Brazil, presented by 

 Dr. A. Stradling, C.M.Z.S. ; a Macaque Monkey (Afaeaeus 

 cynomolgus) from India, deposited ; a Goral Antelope [(Nemo- 

 rluedus goral), two Bar-headed Geese (Anscr indicus) from India, 

 purchased ; a Javan Chevrotain ( Tragulus javanieiis) from Java, 

 a Red Bird of P.aradise (Paradisea sangiiinca), a Twelve-wired 

 Bird of Paradise (Sckucides allms), a Manucode (Mamicodia 

 atra) on approval. 



OUR ASTRONOMICAL COLUMN 

 The Solar Parallax. — In a communication to the Academy 

 of Sciences of Paris on the 7th inst., M. Puiseux has discussed 

 the observations of internal contacts during the last transit of 

 Venus, which were made at stations occupied by the French 

 expeditions. These include observations of second and third 

 contacts at Pekin, St. Paul, Nagasaki, Saigon, and Kobe, and 

 of second contact at Noumea. Seventeen equations are fur- 

 nished by these data, and various combinations are made by 

 Halley's method and by the method of Delisle. The former 



method supplies twelve separate results, the concluded parallaxes 

 varying from 8"78 to 9"'I7, which are arranged according to the 

 amount of the parallax factor : the simple arithmetical mean is 

 8" -98. On Delisle's method the combinations for second contact 

 give fourteen values between S"-S6 and 9"-20, of which the mean 

 is 9"'0i, and those for third contact furnish ten values between 

 8"-63 and S"-90— the mean being 8"-92. These figures considered 

 with respect to others which have been obtained from observa- 

 tions of the same tran^it and oa other methods, cannot be said 

 to enlighten us materially as to the true amount of the sun s 

 mean parallax, M. I'uiseux thinks the observations of contact 

 in 1S74 have not given results so accordant as astronomers had 

 looked for, but he nevertheless is far from discouraging efforts 

 to secur"^ observations of contacts in 1882 ; the phenomena m 

 1874 did not jiresent that geometrical simplicity which had been 

 formerly expected, but presented a succession of phases which 

 were the more difficult to identify in the records of the observers 

 according as the telescopes employed were more dissimdar ; and 

 he urges (i) that the different stations should be provided vvith 

 telescopes of large aperture, to be employed under as identical 

 circumstances as practicable, and (2) that the observers should 

 be exercised "a I'aide d'appareils convenables," to appreciate 

 in the same manner the appearances which the contacts may 

 offer. The former consideration at least is too well understood 

 as of paramount importance to be hkely to be overlooked by 

 any of the national committees now engaged in arranging for 

 the most efficient observation of the transit in 1882. 



Variable Stars.— Minima of Algol occur by Schonfeld's 

 formula on AprU 3 at loh. 51m. G.M.T., and April 6 at 

 7h. 40m., and the next series observable m this country com- 

 mences on May 13 at I4h. 17m. ■ z c 



In the uncertainty that exists with respect to the period of 

 Ceraski's circumpolar variable, the following calculated times of 

 minima are only to be regarded as rough indications :— 



April 



II 58 G.M.T. 



n 38 

 II 19 



A constant period of 2-49326 days is here assunaed. Prof. 

 C H Peters publishes details of his observations of a number 

 of new variable stars (Astron. Nach., No. 2360), and Dr 

 Dmier notifies the variability of the red star Schj. 57 a, which 

 stands thus in the Durchmusterung :— 



h. m. s. o . 



9-4m. ... R.A. S 17 327 ••■ Decl. + 34 s'J 

 This star was invisible in the Lund refractor on January 20, but 

 was well seen on February 23 ; in September and October, 

 1878 he had confirmed its fiery-rei colour, and found the 

 spectrum of the Class III. b. V Herculis vanes from 8m. to 

 12m and the period seems to be about 290 days ; the next 

 maximum may be expected in October of the present year. 



Ancient Astronomy.— In No. 2 of the new periodical, 

 Urania, is an elaborate paper by Prof. Schjellerup of Copen- 

 hagen "Sur le Chronometre C^este d'Hipparque, in which 

 he discusses the question " Comment les anciens astronomes ont- 

 ils determine I'heure de la nuit, et a quelle exactitude ont-ils 

 pu parvenir ? " In this paper he has calculated by the strict 

 trigonometrical formula: (an investigation of which is prefixed) 

 the positions of the forty-four stars mentioned in the thnd book 

 of the only \^■ork of Hipparchus which has descended to us. His 

 " Three Books of Commentaries on the phenomena of Aratus 

 and Ku-loxus," printed for the first time in 1567 (Li^lf.nfe. 

 "Bibliographie," p. 91) from two manuscripts of the Bibhotn. 

 Medicrea and the Library of the Vatican. Petau brought out a 

 new edition, in which he availed himself of an ancient well- 

 written manuscript preserved in the Bibliotheqiie Koyale, and 

 which forms part of the third volume of his " Uranologion 

 Prof 'ichieUerup gives the Greek text essentially after the 

 edition of Petau, with as nearly as possible a literal translation. 

 He concludes his paper with the remark, " Dans I'etat actuel on 

 oeut prouver que les Astronomes d'Alexandrie ont pu determiner 

 le tenuis sideral presqu' \ une minute pres. ' It contains the 

 rieht ascensions and declinations of the stars in question for 

 every hundredth year, from - 300 to -h 100, with the amount of 

 proper motion to the respective epochs, and is a production which 

 merits the attention of those who are interested m the Astronomy 

 of the Ancients. 



The Academy of Sciences, Paris. -At the annual public 

 sitting of the Paris Academy on the 14th inst. the Lalande Prize 



