558 



NATURE 



{April lo, 1884 



In the letter signed "O. S." llast ^week (p. 525), under 

 the heading " Remarkable Sunsets," the French term should be 

 pdure d'oignon and not velure. 



The additions to the Zoological Society's Gardens during the 

 past week include a Macaque Monkey (Alacacus cynomolgus i ) 

 from India, presented by Mrs. F. Mortimer ; two Secretary 

 V^dtures (Serpintarhis reptilivonis) from South Africa, presented 

 by the Rev. G. H. R. Fisk, C.M.Z.S. ; a Blue-and-Yellow 

 Macaw (Ara ararauna) from South America, presented by Mr. 

 H. W. Kingdom ; two Common Peafowls {Pavo crista'us i 9 ) 

 from India, presented by Mr. R. F. J. Cobbett Allen ; a 

 •Common Viper ( Vipera beriis, black variety) from Hampshire, 

 presented by Lord Londesborough, F.Z. S. ; a Yaguarundi Cat 

 (Felis yaguarundi) from South America, a Leuhdorf's Deer 

 {Cerz'us leiihdorfi i] from Amoorland, two Jardine's Parrots 

 (Pieocephalus gulielmi) from West Africa, three Rhinoceros 

 Hornbills (Bziceros rhinoceros 6 9 9) from the Malay Peninsula, 

 two Nepal Hornbills {Acuros ticpalcnsis (J <J ), a Green Cochoa 

 (Cochoa viridis), two Nepal Tree Pies {De di-ocitla n,-paleiisis), a 

 Gray-headed Thrush ( Turdiis castanea) from Nepal, three Bronze 

 Fruit Pigeons {Carpophaga aeuea], two White-breasted Gallinules 

 (Gallinula p/iccnicura) from India, two White-backed Pigeons 

 (Coltimba leuconota) from the Himalayas, seven Waxwings 

 (Anipelis garrulzis], two Proteus {Prolcus anguinus), European, 

 purchased ; a Lucian's Parrakeet (PuLrornis luciani) from China, 

 a Geoffrey's Dove (Paistcra geoffroii i ) from Brazil, received in 

 exchange. 



OUR ASTRONOMICAL COLUMN 

 Comet 1S84 a. — The comet notified by telegram from Mr. 

 EUery as having been discovered in the constellation Cirus, 

 appears to have been detected by Mr. Ross, a young amateur 

 astronomer residing at Elsterwick, near Melbourne, on January 

 7- Observations were commenced at Melbourne on January 12, 

 and were continued to February 4, when the comet had become 

 very faint. The positions, as first communicated to tlie 

 Astronomische Nachrichtin, contained more than one obvious 

 error, and generally (according to a comparison made by Dr. 

 Kreutz with an orbit since received from Melbourne) appear to 

 be strangely inaccurate, a circumstance that will probably have 

 caused useless expenditure of time to computers. We subjoin 

 the Melbourne orbit with one calculated by Mr. Hind from the 

 observations on January 12 and 28 and February 4, as they aie 

 printed in Aslron. Nach., No. 2579 : — 



Melbourne Hind 



Perihelion passage, iSSj.Dsc. 257838 Melb.M.T. ... Dec. 25 4998 CM T. 



Longitude of perihelion 125 15 55 ... 124 I4'4 



,, ,, ascending node 265 12 15 ... 265 56 '5 



Inclination 64 53 16 ... 64 597 



Log. perihelion distance 9'502384 ... 9'5i83S 



Motion — Retrograde. 

 It is to l)e remarked that Dr. Kreutz, calculating from tlie 

 Melbourne orbit, does not reproduce the extreme positions stated 

 to have been employed in its computation. 



Variable Stars. — On comparing the late Prof. Julius 

 ■Schmidt's determinations of the times of minima of Algol in 

 1883 with the formula given by Prof. Schonfeld in his second 

 catalogue of variable stars, it will be found that, by a mean of the 

 observations between August 14 and December 4, the formula 

 gives the minimum too late by fifty-eight minutes. The mean 

 annual errors for the period 1876-83 have shown irregularity, 

 but the separate results within the same year difter considerably. 

 Mr. BaxendeU has worked out new elements for R Arietis 

 from his own observations 1859-81. He finds for — 



Days 

 Maximum ... Epoch 1866, Sept. i"3 -I- 1S671 E. 

 Minimum ... Epoch 1870, Jan. 2'3 -f iS6'63 E. 



The mean interval from maximum to minimum is 99 'o days, and 

 from minimum to maximum 877 days. 



The Observatory, Cincinnati. ^The seventh part of the 

 publications of this Observatory has appeared. Paris 4, 5, and 



6 were devoted by Mr. Ormond Stone to the double-star measures 

 made with the ll-inch refractor in the years 1877-80. In the 

 new part are given the observations of comets in the years 1880- 

 82, including numerous physical observations as well as observa- 

 tions for position. There is a comparison with theory of the 

 phenomena in the tail of the great comet of 1882. In a number 

 of plates are illustrated the telescopic and naked-eye appearance 

 of the great comets of 1881 and 1882 and of the first comet of 

 the latter year. 



Mr. H. C. Wilson is in temporary charge of the Cincinnati 

 Observatory, Mr. Ormond Stone having been appointed Profes- 

 sor of Astronomy in the University of Virginia, and Director of 

 the Leander McCormick Observatory. 



The "Astronomische Gesellschaft." — The fourth part of 

 the eighteenth volume of the Transaclioits of this Society is issued. 

 It contains the proceedings at the meeting held in Vienna in Sep- 

 tember last and the usual critical notices of recent astronomical 

 publications ; also reports on the progress of the zone-observa- 

 tions from thirteen observatories. It was decided to hold the 

 next meeting at Geneva in 1885 ; Prof. Auwers was chosen 

 president for the second time, with Prof. Gylden as vice-presi- 

 dent, and Profs. Schonfeld and Seeliger (now at Munich) as 

 secretaries. 



PHYSICAL NOTES 



The transition-resistance supposed by Poggendorff to exist in 

 electrolytic cells between the surface of the electrode and that of 

 the electrolyte in contact with it h.as lately been investigated 

 with great care by Prof. J. Gordon Macgregor in solutions of 

 very pure zinc sulphate, using electrodes of amalgamated zinc. 

 The conclusion arrived at was that such a transition-resistance, 

 if it exists at all, is less than o'oi25 of an ohm. 



In another paper which appears in the Transactions of the 

 Royal Society of Canada Prof. Macgregor describes an ingenious 

 arrangement devised by him for measuring on Wheatstone's 

 bridge the reistances of electrolytes. He employs alternate 

 currents produced by a rotating commutator inserted in the 

 circuit of two Daniell's cells ; and in order to use with this 

 arrange cent an ordinary mirror-galvanometer, he recommutes 

 the currents in the galvanometer circuit by means of ^a second 

 commutator rotating on the same axle as the first. 



The annual conversazioni of the Societe de Physique, of Paris, 

 will be held this year on April 15 and 17 respectively, the former 

 being limited strictly to the members of the Society. These 

 meetings will, by the invitation of Admi-al Mouchez, be held in 

 the Observatoire. 



A NOTE on Hall's effect was recently read 'at a meeting of the 

 Physical Society of London by Prof. S. P. Thompson and Mr. 

 C. C. Starling. They find that when a large sheet of foil is used, 

 and placed symmetrically in a concentrated field between pointed 

 magnetic poles -so that the junctions and connections are quite 

 outside the influence of the field. Hall's effect is not produced. 

 They find, however, an alteration in the equipotential lines of 

 the current in the strip where it is magnetised, and have traced 

 this effect to a change in the resistance. Strips of gold and tin 

 show a decrease, strips of iron a slight increase of resistance 

 when subjected to a strong magnetic field. 



Another paper on Hall's effect appearsiu the current number 

 of the Jo2iyn(il de Physique Uom the pen of M. Leduc. In this 

 article M. Leduc draws a diagram of the equipotential lines, as 

 according to his ideas, they will be found to lie between the two 

 " parasitical " electrodes. It does not appear whether he has 

 verified his views by actual determinations of the position of the 

 hues of equal potential. 



Rowland's famous experiment demonstrating the magnetic 

 action of electric convection has been called in question by Dr. 

 E. Lecher of Vienna. In Rowland's original experiment the 

 electrified rotating disk was horizontal, and the magnetic needle, 

 protected from electrostatic influences by being inclosed in a 

 metallic case, was held over the disk at a point near the circum- 

 ference. Dr. Lecher, in attempting to repeat the experiment, 

 placed the rotating disk in a vertical plane, its axis being hori- 

 zontal ; the magnet needle was placed parallel to the plane of 

 the disk and in the axis of its rotation in fact relatively as the 

 coil and needle of a Gaugain galvanometer. Disks of brass and 

 of /«//■«•- wwr/it' covered^\\ith graphite were used, and charged 



I 



