546 



NATURE 



[AiKiL 6, 189^ 



Notes from the Marine Biological Station, Plymouth :— Last 

 week's captures include the rare Nudibranch Hero formosa, 

 specimens of the spiny shrimp {Crangon spinosus), and of 

 the starfishes Porania pulvillus zxiA Henricia (Cribrella) san- 

 guinolenta. In the floating fauna Phitei, large and small, have 

 now quite taken the place of the Auricularia and Bipinnaria 

 larvae, which were so plentiful a few weeks ago. Arachnactis is 

 still obtainable. The unmodified ephyrae of Aurelia are now 

 very scarce : most of them are passing through various phases 

 of their metamorphosis into the definitive medusa-form ; and, 

 instead of being plentiful everywhere, are now restricted to 

 special localities. 



The additions to the Zoological Society's Gardens during the 

 past week include a Bonnet Monkey {Macacus sinicus, $ ) from 

 India, presented by Mr. J. Pitcher ; a Bengalese Cat {Felts 

 bengalensis) from Manilla, Philippine Islands, presented by Mr. 

 D. M Forbes, F.Z.S. ; three Vt2Sovi\%{Pavo cristatus, <J 9 ? ) 

 from India, presented by Mr. T. Guy Paget ; a Leadbeater's 

 Cockatoo (Cacatua leadbeateri) from Australia, presented by 

 Mrs. W. Everett Smith ; five Black-headed Gulls {Larus ridi. 

 bundus), a Common Gull {Larus canus) Eur&pean, presented by 

 the Rev. E. M. Mitchell ; three Rhomb-marked Snakes {Psam- 

 mophylax rkombeattis), a Hoary Snake ( Coronella cana) from 

 South Africa, presented by Messrs. H. M. and C. Beddington ; 

 three Spring boks {Gazella euchore, (???) from South Africa, 

 a Raccoon {Procyon lotor) from North America, a Green 

 Monkey {Cercopithecus callitrichus) from West Africa, de- 

 posited ; two silver-backed Foxes {Canis chamd), a Cape Buce- 

 phalus {Bucephalus capensis) from South Africa, purchased ; a 

 Short Death Adder {Hoplocephalus curtus) from Australia, 

 received in exchange ; four Great Cyclodus ( Cyclodus gigas) 

 born in the Gardens. 



OUK ASTRONOMICAL COLUMN. 



Comet Swift (a 1892).— At the Boyden Station, Arequipa, 

 Peru, during the visibility of this comet, all the photographic 

 telescopes were turned towards it, with the result that a fine 

 series of photographs were obtained. In the Bache 8inch 

 photographic doublet, fifty-six piciures (20 millimetres to the 

 degree) were taken, sixteen of which " are of the first quality " ; 

 in the 2'5-inch photographic doublet (3-8 millimetres to the 

 degree) twelve satisfactory plates were taken, while in the 

 13-inch refractor and 20-inch reflector several additional 

 negatives were collected. An examination of the negatives, 

 especially of those belonging to the first series, indicated two 

 important facts, as Mr. A. E. Douglass {Astronomy and Astro- 

 physics for March) informs us. (i) That the tail o( the comet 

 was composed of luminous masses receding from the head at a 

 measurable rate, and (2) that the form of the tail depended 

 largely on some varying lorce acting at the head. The former 

 of these results was deduced from measurements of the distance 

 of prominent points (8 points were here used) from the nucleus, 

 and the acceleration he obtained amounted to 477,000 miles per 

 day. In discussing the second fundamental results, he deals with 

 the general characteristics of the tail and the special phenomena 

 within half a degree of the head, separately. The tail he 

 describes as "a bundle of slightly divergent straight streamers, 

 branching from each other and joined to the head by one, two, 

 or three well-marked lines." At the southern part of the tail 

 the photographs showed the appearance of a curious twisting 

 effect, while a number of faint streamers, in many cases not 

 joined to the main part of the tail, were also visible. The curve 

 of the natural tangents of the position angles for the date on 

 which they left the head, is, as plotted out by Mr. Douglass, 

 quite irregular, and suggests "non-periodic outbursts from the 

 head of the comet or variations in the repulsive force of the 

 sun " ; where the tail swings to one side there are "large jets in 

 the opposite direction as if the whole resulted from some in- 

 crease in activity in the head." He suggests that this activity 

 may be connected with solar disturbances, just as magnetic 



storms on the earth may be connected with certain classes of 

 sunspots. 



Paris Observatory in 1892. — From the annual report on 

 the condition of the Paris Observatory during the year 1892, 

 which was presented to the Council in January last by M. 

 Tisserand, the Director, we gather the following brief notes : 



Commencing with a short reference to the late Director, 

 I'Amiral Mouchez, and to the great loss both to the Observatory 

 itself and to astronomical science in general, M. Tisserand 

 informs us that, at the suggestion of M. O. Struve, the 

 presidency of the Comite permanent de la Carte du Ciel has 

 passed to the present Director of the Paris Observatory. This 

 choice has been received very favourably, and been confirmed 

 by all the members of the committee. Let us here tender our 

 congratulations to M. Tisserand, who, without doubt, will, in 

 his capacity as president, bring such a grand work as nearly as 

 possible to perfection. In fact, he has commenced by increasing 

 the personnel du Bureau de Mesures des Cliches at the Obser- 

 vatory, and constructing a new machine for the measures, while 

 he hopes soon to publish a fascicule of the Bulletin de la Carte du 

 Ciel, which will contain the method of reducing the measures, 

 and of the definite computations of the positions of the stars. 



The large equatorial Coude has this year been subjected to a 

 minute study by M. Loewy from the point of view of its optical 

 qualities, and of the possibility of improving it still more. The 

 experiments have as yet been restricted to the mounting of the 

 mirror, and it seems that important results may soon be forth- 

 coming. The spectroscopical department, under the direction 

 of M. Deslandres, has, as we are informed, quite assumed a 

 definite form since its foundation in 1890 ; the work done 

 is tabulated under the three headings — sun, stars, and laboratory 

 work. As we have previously referred in these columns to 

 most of the work here accomplished, such as, for instance, the 

 researches of the velocities of stars in the line of sight (250 stars 

 will here be included), photographs of protuberances, faculse, 

 new hydrogen radiations, &c., further notice will be unneces- 

 sary. With the Equatorial de la Tour de I'Ouest, the programme 

 of observations has been the same as in previous years, measures 

 of the positions of comets, nebulse, and double stars having been 

 obtained. Among the observations here recorded as many as 

 136 were made of Comet Swift (1892), 41 of Comet Denning 

 (1892), while 250 nebulse and 120 double stars have been 

 measured. All the above were made by M. Bigourdan. M. 

 Faye also made 77 observations of comets. With the Cercle 

 Meridien du Jardin under the special service of M. Loewy, the 

 total number of observations amounted to 16,686; 453 obser- 

 vations were made of the sun, moon, and planets. M. Paul 

 and Prosper Henry have been occupied in obtaining 

 cliches of the international chart and of the catalogue ; photo- 

 graphs have also been taken of the late nova in Auriga, Jupiter, 

 and Comet Holmes. The Bureau des Mesures des Cliches du 

 Catalogue, under the direction of Mdlle. Klumpke, has been 

 very busy. At this part of the report a brief description of the 

 measuring machine is given, and in a paragraph on "reflexions 

 sur le catalogue et la duree de son execution," we are told that, 

 if simply the 1200 or 1400 cliches which are demanded for the 

 work in each of the eighteen observations are obtained "on 

 peut esperer d'y atteindre en cinq ou six ans au plus." For 

 measuring the cliches with one machine, and two persons to 

 observe and write the results, 130 cliches could be done in a 

 year, but it would take about 10 years to measure the cliches 

 attributed to one observatory, with one machine and two per- 

 sons working incessantly. The report contains also all the 

 meteorological work and that done with the minor instruments, 

 concluding with the usual lists of personal publications, obser- 

 vatory publications, changes in the personnel, &c. 



The Large Nebula near | Persei (N. G. C. 1499). — 

 Dr. F. Scheiner, in Astronomische Nachrichten (No. 3157), 

 describes briefly this great nebula rear | Persei, several 

 photographs of which he has been able to obtain. During 

 November and December last, employing an objective of 

 4-inch aperture, he took fine photographs, with exposures 

 varying Ircm I to 6 hours. The longest exposed plates showed 

 that the size of this nebula has been considerably under-rated, 

 and that it comes nearly up to that of Orion and Andromeda. 

 This nebula, it will be remembered, was discovered by Prof. 

 Barnard with a 6-inch objective, and the position which he 

 gave, 3 h. 54-0 m. R.A. -f 36° l' Decl. (18550), referred to 



NO. 1223, VOL. 47] 



