1 86 



NA TURE 



[December 22, 1892 



viscous liquids are produced which remain liquid even at — io°. 

 As regards the preparation of the base, M. de Bruyn has now 

 succeeded in obtaining a hundred grams of the pure crystals 

 from a little more than a kilogram of the hydrochloride, by the 

 method described in our previous note above referred to. 



The additions to the Zoological Society's Gardens during the 

 past week include a red and yellow macaw {^Ara macao) from 

 Central America, presented by the Rev, T. N. Talfourd Major ; 

 two gold pheasants {Thautnalea picta9 ?) from China; an 

 Alpine Chough {Pyrrhocorax alpinui), European, piirchased. 



OUR ASTRONOMICAL COLUMN, 



Comet Holmes (November 6, 1892). — The following ephe- 

 meris, taken from Astronomische Aachrichten, No. 3 131, gives 

 the position for Comet Holmes for the ensuing week : — 



Berlin, Midnight. 

 Decl. (app.). 



Log 



Log A. 



+ 34 I9'2 

 160 



I2'9 

 lO'O 

 7-2 



4-5 



0-4050 



0-4073 



03049 



0-3167 



1892. \^- (^pp-)' 



^ h. m. s. 



Dec. 23 ... o 55 44 



24 - 56 37 •- 



25 ... 57 31 ... 



26 ... 58 27 ... 



27 ... 059 24 ... 



28 ... I o 22 ... 



29 ... I I 21 ... 34 1-9 



M. Deslandres, in Comptes rendus for December 12 (No. 24), 

 informs us that on November 21 he obtained a photograph of 

 this comet between loh. 40m. and iih. 20m. Paris mean time, 

 showing distinctly " un commencement de dedoublement." 

 Owing to the bad weather no other negatives were taken until 

 December 10, but although the time of exposure was an hour, 

 the comet's impression was not obtained, thus confirming the 

 present eye observations that its intensity is slowly decreasing. 



Comet Brooks (November 20, 1892).— The following 

 ephemeris of Comet Brooks is that obtained by Berberich, and 

 varies a little from that given last week, as will be seen by com- 

 paring the values for December 22, with those given last 

 week : — 



Berlin, Midnight. 



g R.A. Decl. Log A. Log ;•. Br. 



^ ^ - h. m. s. o / 



Dec. 22... 14 26 9 ... +42 50-2 



23... 14 33 28 ... 44 40-4 



24... 14 41 35 ... 46 34-4 



25... 14 50 41 ... 48 31-6 



26... 15 o 55 ... 50 31-4 



27... 15 12 26 ... 52 32-9 ... 9 



28... 15 25 30 ... 54 345 



29... 15 40 21 ... 56 34-4 ... 9-8694 ... 00831 ... 7-26 

 Swift's Comet. — Knoivledge for December i contains three 

 most interesting photographs of Comet Swift, taken by Prof. 

 Barnard at the Lick Observatory on April 4, 6, and 7 re- 

 spectively. These photographs, which are obtained from the 

 original negatives after an enlargement of i\ times, show what 

 good photographic work can be done even with small instru- 

 ments when exposures are somewhat lengthened. In this 

 case a 6-iiich Willard lens of 31 inch focal length was strapped 

 on to the tube of a 6J-inch equatorial, and the exposures given 

 amounted to 60, 65, and 50 minutes. The ordinary driving- 

 clock, combined with a slight hand movement at the eye end, 

 were all that was required to compensate for the diurnal and 

 proper motion of the comet. The star trails on the plates 

 pointed out then the comet's proper motion. Although these 

 photographs were taken at such short intervals the changes re- 

 corded are most striking, the pictures bearing very little likeness 

 to one another. On this point Prof. Barnard says : " Had they 

 been drawn by the most competent observer, most astronomers 

 would leave their remarkable differences to the unskilful hand 

 of the artist, for there is absolutely no resemblance among them." 

 The photographs here referred to are from a series taken at Mount 

 Hamilton, and in examining them he mentions that in the case 

 of this comet he has been led to forcibly believe that in a com- 

 paratively short period there occurred a rotation of the tail 

 ■"upon an axis through the nucleus." 



NO. 1208, VOL. 47] 



9-9211 ... 0-0880 .. 5-59 

 9-9013 ... o-o86i ... 6-i8 

 .. 0-0845 ••• 6-75 



Ultra-Violet Spectrum in Prominences. — In the 

 current number of the Memorie delta Societa Degli Spettroscopisti 

 Italiani, Prof. G. E. Hale communicates a note on some photo- 

 graphs of the ultra-violet region in the spectra of solar promi- 

 nences. On October 15 at 3h. 15m. a photograph of the 

 spectrum of a metallic prominence was obtained, which con- 

 tained as many as 74 bright lines in the ultra-violet between 

 wave-lengths 3970 and 3630. The photograph, besides display- 

 ing all the lines previously recorded by Pmf. Hale and M. 

 Deslandres, contained 32 additional lines which had not been 

 previously known. The following table shows their respective 

 wave-lengths, which are to be regarded yet as only approxi- 

 mate : — 



^ A A. 



3964 ... 3863 ... 3724-3 

 39569 ... 3850-5 .-■ 3716-9 

 39452 ... 3813-5 ... 3710-3 

 3938-1 ... 3774 ... 3699-5 

 3913-5 ... 3767-1 ... 3683 



3965 ... 3758 ... 3681 

 3895-5 ... 3757 ... 3679-S 

 3893'8 ... 3749-7 ... 3674-2 

 3891 ... 3741-7 ■•• 3662-2 

 3878-8 ... 37333 ... 3647-8 



3632 

 3630-8 

 Besides these lines the photograph shows traces of the lines 

 X 3807-2, 3802, 3764, 3763, 3758-2, 3709-5, 37^78, 3676, 

 3643- 



Ephemeris for Bodies Moving in the Biela Orbit.— 

 In Astronomical Journal, No. 281, Dr. Chandler communi- 

 cates an ephemeris for the use of those wishing to search for 

 bodies which may be moving in the orbit of Biela's comet. 

 The ephemeris is given for every eight days. It is based on the 

 orbit obtained by Michez, who calculated the principal perturba- 

 tions up to 1866. In the present computations Dr. Chandler 

 has not taken into ace mnt any disturbance that may have been 

 produced by the proximity of the planet Jupiier, or any per- 

 turbation that might have ensued from an approach to our earth. 

 The values are given up to the end of February, 1893. 



Madras Meridian Circle Observations.— The Govern- 

 ment of Madras has lately issued the results of observations 

 of the fixed stats, made with the meridian circle during the 

 years 1874-76. During this interval no change whatever was 

 made either in the instrument or in the methods of reduction. 

 The volume gives the instruinental corrections for these years, 

 the separate results of observations for each year, with the mean 

 positions of the stars brought up to January i of each year, 

 and corrections to the Nautical Almanac stars for the period in 

 question. 



THE JUBA RIVER. 

 A T the meeting of the Royal Geographical Society on Monday 

 -'*■ evening. Commander F. G. Dundas, R.N., read a paper 

 describing his ascent of the Juba river. This was the first 

 serious attempt to explore the river since Von Her Decken's ill- 

 fated expedition in the Guelph in August, 1865. The stern- 

 wheel steamer Kenia, belonging to the Imperial British East 

 Africa Company, under the command of Captain Dundas, 

 crossed the bar of the Juba on April 25, 1892, an operation of 

 much danger, as the vessel was exposed broadside on to heavy 

 rollers ; the depth at high water is only one faihom, and the 

 water swarms with sharks and crocodiles. The coast Somalis 

 lined the bank with hostile movements as soon as they saw that 

 the vessel was to go up the river, and detained the expedition 

 for a fortnight, until a message was sent to the head chief, the 

 Sultan of the Ogaden Somalis. It was July 3 before amicable 

 arrangements could be made, and the expedition fairly started. 

 The Somalis met with everywhere were very strict Mohamme- 

 dans, and secluded their women, but a number of Galla slave- 

 girls were seen amongst them. There were few villages, 

 Hajowan and Hajaualla opposite each other near the mouth 

 being the only large ones until Munsur, 360 miles, and Bar- 

 dera, 387 miles from the sea, were reached. The lower reaches 

 of the river were very winding. On one occasion Captain 

 Dundas observed a stream flowing parallel to the river he was 

 on, and going across to see it recognized the landmarks as those 



