376 



NATURE 



[February i6, 1893 



either hydrogen or nitrogen, neither of which combine with 

 manganese, were employed. It is therefore evident that 

 manganese does not resemble iron and nickel in forming a 

 volatile compound with carbon monoxide, but that the volatility 

 is a property of the element itself, and is singularly manifested 

 even at the temperature of the melting point. 



Some of the more interesting captures recently made by the 

 dredgingstaff of the Marine Biological Association at Plymouth 

 are the Actinian Chitonactis coronata ; the Nudibranchs 

 Berghia ccerulescens (new to Britain), Amphorina carulea, and 

 Lamellidoris oblonga in considerable numbers ; and the hand- 

 somely marked rare spider-crab, Stenorhynchus egyplius. The 

 alga Halosphcera viridis has been present in all townettings since 

 October ; and Noctiluca, though in small numbers, is now 

 generally present. The breeding season of a large number of 

 Invertebrata has already commenced, and the sea swarms with 

 Copepod and Cirrhipede Nauplii, and with Polychgete larvas. 

 Species of the following genera are breeding: — The Hydroids 

 Halecium, Plumularia, Sertularella, Hydrallmania ; the 

 Actinians Chitonactis and Actinia; the Nemertine Lineus 

 obscuriis (larva of Desor) ; Phyllodoce maculata and other 

 Annelids ; the Molluscs Capulus hungaricus, Lamellaria, 

 Buccinum, Purpura, many Nudibranchs ; and the Decapod 

 Crustacea Crangon, Pandalus, and Palcemon ; Carcinus, Cancer. 

 and Eurynome. 



The additions to the Zoological Society's Gardens during 

 the past week include a Fallow Deer {Dama vulgaris i ) 

 European, presented by Mr. B. L. Rose ; a Great Eagle Owl 

 {Bubo maximus) European, presented by Mr. Adolphus 

 Drucker; two GoldPheasants {Thaiimalea picta ? ? ) from China, 

 presented by Miss Forster ; nine Snow Bantings {Plectrophanes 

 nivalis) British, presented by Mr. T. E. Gunn ; an Egyptian 

 Cobra {Naia haje), two Hoary Snakes {Coronella cana), from 

 Victoria West, Cape Colony, presented by the Rev. G. H. R, 

 Fisk, C.M.Z.S. ; three European Pond Tortoises {Emys 

 europcea) European, deposited ; a King Snake [Coluber getulus) 

 from North America, received in exchange. 



OUR ASTRONOMICAL COLUMN. 

 The Total Solar Eclipse of April 15-16, 1893. — The 

 following particulars of the phenomena of the total solar eclipse 

 of April 15-16, 1893, have been supplied to the Eclipse Com- 

 mittee by Mr. A. M. W. Downing, Superintendent of the 

 Nautical Almanac office, for the use of the English observers 

 at the eclipse stations to be occupied in Brazil and Africa : — 

 Brazil. Longitude 38° 50' W. Latitude 3° 20' S. 



Contact Contact Sun's 



from from alti- 



d. h. m. s. N. point. vertical. tude. 



Eclipse begins April 15 22 18 14 ... 136° W. ... 19° W. ... 62° 



Totality begins 15 23 40 51 1 j. . 



Totality ends 15 23 4S 34 i 



Eclipse ends 16 i ii 40 ... 45°E. ... 84° W. ... 68° 



Local mean times. 



tion 4m. 43'is. 



Totality ends 

 Eclipse ends 



Senegambia. Longitude 16° 30' W. Latitude 14° 15' N. 



Contact Contact Sun's 



from from alti- 



d. h. m. s. N. point. vertical. tude. 



Eclipse begins April 16 i 5 3 ... 130° W. ... 156° E. ... 73° 



Totality begins 16 2 27 59 j duration 4m. 12-35. 



Totality ends 16 2 32 12 \ ^ ^ 



16348 I... 57° E. ... 24=W. ...35° 

 Local mean times. 



Remarkable Comets. — Bearing this title, Mr. Lynn has 

 written a small book, in which he gives a short survey of the 

 most interesting facts that have occurred in the history of 

 cometary astronomy. As he remarks in the preface, the scope 

 of the work is almost purely historical ; but we are sure there 

 are many who will peruse these few pages with great pleasure, 



NO. I 2 16, VOL. 47] 



for the author has brought together these facts and presented 

 them to the reader in a concise and plain style. We may men- 

 tion that figures relating to elements of orbits, ike, are at a 

 nwnimum, Mr, Lynn simply restricting himself to bare accounts. 

 The author concludes by giving a list of the dates at which 

 some of the comets may reappear, from which we make the 

 following extract: — 



Date. Period in years. 



1893 ... Summer ... 6\ ... Finlay's Comet 



1894 ... Winter ... 3I ... Encke's „ 



1896 ... Spring ... 7I ... Faye's ,, 

 ,, ... ,, ... 7 ... Brook's ,, 



1897 ... ,, ... 6^ ... D'Arrest's ,, 



,, ... 5I ... Swift's „ 



1898 ... Summer .. 5^ ... Winnecke's,, 

 ,, ... Autumn ... 7 ... Wolf's ,, 



1899 ... Spring ... 33J ... Comet of 1866 

 ,, ... Summer ... 13! ... Tuttle's Comet 

 ,, ... ,, ... 7 ... Holmes's ,, 



The comet of 1866, as many of our readers well know, is iden- 

 tical with the meteoric stream through which we pass in 

 November, so we hope that we shall be visited by a fine 

 display. 



Comet Holmes (1892, IH.). — Comet Holmesseems to have 

 become somewhat dimmed during the past week, but we never- 

 theless give the ephemeris for the benefit of those who wish to 

 follow it a little longer. 



Ephemeris for I2h. M.T., Paris. 



Comet Brooks (November 19, 1892). — This comet lies in the 

 southernmost part of the constellation of Andromeda, just south 

 of e Andromedse, and the following is the current ephemeris : — 



Ephemeris for I2h. M. T., Berlin. 



R A. app. Decl. app. Log r. Log .i Br. 



1893. h. m. s. 01 



Feb. 16 ... o 22 44 ...-1-26 46*9 



17 ... 24 8 ... 26 23-2 ... 0-1343 ... 0-2445 .. 0-97 



18 ... 25 30 .. 26 0-3 



19 ... 26 50 ... 25 38 3 



20 ... 28 8 ... 25 17-1 



21 .. 29 23 ... 24 56-7 ... 01438 ... 0-2711 ... 0-83 



22 ... 30 37 ... 24 37-1 



23 ... o 31 49 ... 24 18-2 



Relative Positions of Stars in Cluster x Persei. — 

 Volume XXX. part iv. of the Transactions of the Royal Irish 

 Society contains the results of the investigations of Sir Robert 

 Ball and Mr. Arthur Rambaut, with respect to the relative 

 positions of 223 stars in the cluster x Persei as determined 

 photographically. The instrument used throughout was a 15- 

 inch silver on glass reflecting telescope, mounted according to 

 Cook's standard equatorial pattern. For the adjustment of the 

 plate (the size used here being 3^ x 3^) and mirror Dr. John- 

 stone Stoney's collimator was employed, this method ensuring the 

 exact perpendicularity of the photographic plate to the axis of the 

 collimator. The negatives were measured with an instrument 

 made by the same firm, and after the same pattern as that used 

 by Prof. Pritchard, at Oxford, this instrument being supplied 

 with the means of measuring either rectangular or polar co- 

 ordinates, the former of which has been adopted here through- 

 out. In this memoir the authors treat in detail, by means of 

 figures and formulae, the equations for orientating the plate for 

 measurement, for computing the differences in Right Ascension 

 and Declination from the centre of the plate, for correcting the 

 relative apparent positions of the stars for effects of separa- 

 tion, observation, nutation, and procession, &c. The measures 

 here given have been obtained from one photograph taken with 

 an exposure of ten minutes, the images under the microscope 

 being susceptible "of very accurate measurement." That only 



