156 



NATURE 



\_Jitnc 17, iSh'o 



seuted by Mr. A. II. Jamrach ; a Horsfield's Tortoise (Tcsludo 

 horsfiddi) from Afghanistan, presented by Capt. Cotton ; two 

 Smooth .Snakes [Coronclla hziis], British, presented respectively 

 by ]\Ir. \V. Penny and Mr. Thos. J. Mann ; two Yellow-headed 

 Troupials {Xanthocephalus icicroceflialus) from Mexico, presented 

 by Mr. W. A. Conilin ; a Jaguar {Fdis onca) from Bolivia, two 

 Common Boas {Boa constrictor) from Savanilla, deposited ; a 

 Kin^tailed Lemur {Lemur catta) from Madagascar, a Ludio 

 Jlonkey {Cercopitkcciis ludio), a Mona Monkey {Cercopithecus 

 ■inona), two Rus's Weaver Birds {QucJea russi), two Cinereous 

 Waxbills {Estrelda cccrulescens), two Crimson-eared Waxbills 

 (Estrelda phccnicoiis) from West Africa, a Black-footed Penguin 

 {Spheniscus deinersus), a Levaillant's Parrot {Pojoccphalus robustus)^ 

 from South Africa, a Brahminy Kite {Haliastur indus) from 

 South Asia, a Brown Crane {Grus canadensis) from North 

 America, a Double-crested Pigeon {Lophola-iniis antarcticus) from 

 North Australia, two Swift Parrikeets {Lathainus discolor) from 

 Ta.smania, two Victoria Crowned Pigeons {Goura victoris) from 

 the Island of Jobie, four Bengal Weaver Birds {Ploceus ben- 

 galensis) from India, a Red Lory {Eos rubra), an Ornamental 

 Lorikeet { Tric/ioglosstts ornatus) from Moluccas, a White-billed 

 Parrakeet (Tanygnat/ius albirostris) from Celebes, a Noble Macaw 

 {Ara nobilis) from Brazil, two Yellow-fronted Amazons {Chiysotis 

 ocJsroccphala) from Panama, a White headed Parrot {Pioniis 

 senilis) from Mexico, two Black-headed Conures {Conurus 

 tianday) from Paraguay, t\^•o Silky Marmosets (Midas rosalia) 

 from South-East Brazil, a Leucoryx Antelope {Oryx leucoryx) 

 from North Africa, a Common Otter {Lutra vulgaris), British, 

 three Chinchillas {Chinchilla lanigera) from Chili, an Upland 

 Goose {Bernicla magcllanica) from the Falkland Islands, three 

 Ashy-headed Geese {Bernicla poliociphala) from South America, 

 purchased; an Anoa {Anoa depressicornis) from Celebes, received 

 in exchange; an Axis Deer {Ceivus axis), a Japanese Deer 

 (Cervus siia), a Geoffroy's Dove {Peristera geoffroii), a Wonga- 

 wonga Pigeon (Leucosarcia picata), a Turquoisine Parrakeet 

 {Euphcma pulchclla), bred in the Gardens. 



OUR ASTRONOMICAL COLUMN 



Faye's Comet. — Dr. Axel-Moller cjmmences his ephemeris 

 of Faye's comet for the present year on July I, when its distance 

 from the earth will be 2'005, and that from the sun 2"53 ; the 

 perihelion passage will not take place till January 22, 1881, The 

 intensity of light corresponding to the comet's distances on July I 

 is o'o39 ; in 1S44 it was observed with sensibly the same intensity, 

 the value for the last observation with the 15-inch refractor at 

 Pulkowa being o'035. The comet attains its greatest brightness 

 in the middle of October, when the value corresponds to that at 

 the la-t observation in 1858, with the 9"6-inch refractor at Berlin 

 on October 16. At discovery by M. Faye in 1S43 the theoretical 

 intensity of light was o"54, which has not been approached at 

 any of the subsequent returns. The following positions are 

 taken from Dr. Axel-Moller's ephemeris, which is calculated for 

 Berlin midniglit, or about lih. G.M.T. : — 



Ascei 



July I 

 3 

 5 ■ 

 7 ■ 

 9 

 II 



'3 



>5 



23 5 25 . 

 23 6 38 , 

 23 7 47 

 23 8 52 

 23 9 54 

 23 10 51 

 23 II 44 

 23 1233 



• + 7 53'5 ! July 17- 



, 8 77 



8 21 '4 

 . 8 34-8 

 . 8 477 

 . 9 o-i 



9 I2-I 



. + 9 23-6 



•2313 17- 



• 23 13 57 • 



• 23 1432 . 

 ,. 23 15 2 . 

 ■ 231527. 

 •23 15 47- 

 ,. 23 16 2 . 

 .. 23 16 12 . 



■+ 9 34'5 



• 9 44'S 



• 9 S4'6 

 . 10 3'6 



10 120 

 . 10 197 

 . 10 26'6 

 .-no 32'S 



The comet will arrive at its least distance from the earth (rog) 

 on October 3. So far as can be foreseen without calculation of 

 the perturbations the comet is not likely to exhibit a degree of 

 brightness aiiproaching that in the year of its discovery by M. 

 Faye, until 1903. 



While Faye's comet is followed up by Dr. Axel-MoUer in the 

 same admirable manner as for many years past, calculations 

 relating to other comets of short period are in the hands of the 



following astronomers according to the last Report of the Astro- 

 nomisches Cesellschaft : — Dr. Backlund of the Imperial Obser- 

 \-atory, Pulkowa, proceeds with the perturbations of Encke's 

 comet, taking up the work where it was left by the late Dr. v. 

 Asten ; Brorsen's comet is undertaken by Prof. R. Schulze of 

 Dobeln; D'Arrest's by M. Leveau of Paris; Winnecke's by 

 Prof. Oppolzer of Vienna; Tempel's comet of 1867 by M. 

 Gautier of Geneva ; Tempel's second comet (1871), Ijy M. 

 Schulhof of Paris ; and Tuttle's comet, due in the year 18S5, by 

 Mr. Ormond Stone of Cincinnati. The exceptional case of 

 Biela's comet is not provided for. 



The Great Southern Comet of 1S80. — Dr. M. W. 

 Meyer, of Geneva, assuming for the period of revolution of this 

 comet the interval bei\ieen the perihelion passage of the great 

 comet of 1S43 ^"'^^ '''^' °f ''^^ comet in 1880, corresponding to a 

 semi-axis major of 1 1 '0869, has adapted the other elements of 

 the orbit thereto by means of Dr. B. A. Gould's observations at 

 Cordoba on February 6, 12, and 19, covering an interval which, 

 so far as we know at present, is only one day Jess than the whole 

 extent of accurate observation : the Cordoba observations of 

 February 5 await the meridional observation of the comparison 

 star, which is not found in our catalogues : it may be well deter- 

 mined at one of the observatories of Southern Europe. Dr. 

 Meyer's results are as follows : — 



Perihelion passage, iSSo, January 27*44242 G.M.T. 



Longitude of perihelion 27S 22 47 ) Mean equinox, 



,, ascending node ...356 16 43) i88o'o 



Inclination of the orbit 36 52 13 



Log. excentricity ( = log. sine (/>) 9'99976S2 or (f) = 8S" 7' 4i"'55 



Log. perihehon distance 7'7720og5 



Motion retrograde. 

 The aphelion distance in this orbit is 22'i679 (the earth's mean 

 distance being taken as unity), and at aphelion the comet is distant 

 from the orbit of Uranus 13^15. The nearest approach to the 

 orbit of Jupiter, about 3'i, takes place when the true anomaly 

 is about "176- 35'. The comet's orbital velocity at perihelion is 

 338 miles in a second, and that at aphelion 477 feet in the same 

 interval. 



Minima of Algol. — The following times of geocentric 

 minima of Algol, observable in this country during the ensuing 

 quarter, are deduced from the elements given by Prof. Schonfeld 

 in his catalogue of 1875. Considerable perturbations of epoch 

 appear to have taken place during the last five years, as we have 

 previously noted in this column, aud from the course of the 

 errors of calculation it seems quite possible that the computed 

 times may be nearly a half-hour too late. Systematic observa- 

 tions of this variable are now much to be desired, and it may be 

 hoped that one or more of the many zealous amateur-astronomers 

 here will devote attention to it. The perturbations to which we 

 have alluded were particularly evident in 1S76, and the error of 

 the calculated times attained a maximum in the following year, a 

 mean of seven observations by Prof. Julius Schmidt at Athens 

 shouing that the computed epoch was too late by forty- eight 

 minutes. The following epochs are directly comparable with 

 observation : — 



July iC 



19 



Aug. 2 



5 



12 39-0 G.M.T. 

 9 27-5 



14 I9'6 ,, 

 II 8-2 ,, 



15 59"4 „ 



Aug 



Sept. 



PHYSICAL NOTES 

 According to our contemporary V Eleclricite, M. Exner of 

 Vienna has discovered that a bismuth-antimony pair immersed 

 iu a gas incapable of acting chemically on either of these metals 

 jields no current when one junction is heated. Also that if two 

 bars of copper are soldered together to forma " pair" no current 

 is produced when either junction is heated in air (as would be 

 expected in a circuit of one metal), not even when both strips 

 are exposed to the action of chlorine ; but that if one strip only 

 is exposed to chlorine gas and then one junction be w.-irmed a 

 thermo-electric current is set up. According to Exner therefore, 

 all so-called thermo-electric currents are due to chemical action. 

 It would be easy for some of our ardent young physicists to put 

 to the test this very remarkable announcement, and see whether 



