July 6, 1893] 



NA TURE 



OUR ASTRONOMICAL COLUMN. 



Comet Finlay (1886 VII.).— M. Schulhof, in the current 

 number of the Astr. Nach. (3171) gives the new elements and 

 ephemeris of Comet Finlay. They are as follows : — 



M = 



7C = 



ft = 



i = 



= 



M = 



log. o = 



1893 



1893-0 



fuly 6 



7 

 8 



9 

 10 

 II 



12 



13 



6 5« S-33 



7 41 34-1 

 52 27 427 



3 2 2T 

 46 o 49 4 



535 8046 

 05473335 



12//. M.T. Talis. 



R.A. app. 

 / // 

 3 26 589 



31 39-4 



36 19-1 



40 57'9 

 45 35 '9 

 SO 12-9 



54 48-9 

 3 59 238 



Decl. app. 



+ 16 49 29 

 17 8 337 

 17 27 33"J 



1 7 46 I 'O 



18 3 57-1 

 18 21 21 '3 

 18 38 13-1 

 18 54 32 -8 



A Bright Comet? — In a note under this heading which 

 appeared in these columns on June 22, we gave an interpreta- 

 tion of a telegram from Kiel to one of the German Observa- 

 tories. The message ran: "From Boston probably bright 

 comet photograph, Lewis, 5 June, 09571 ; Boston 26423, 07558, 

 43552 ; 12 June, 10043 ; Boston 27119, 06904, 44066. Ver- 

 batim ventilate unpliable. " 



Unfortuna'ely, after having translated the code on a separate 

 sheet of paper, we set down the Boston times as the right 

 ascensions, an error often liable to occur when one is used to 

 reading right ascensions in hours, minutes, and seconds, and 

 not in degrees of arc. 



This telegram was distributed only to a few observatories 

 in order to substantiate the discovery, or otherwise, before 

 the announcement was openly made, and it was in the endeavour 

 to present our readers with this piece of news as early as 

 possible that this clerical error was made. 



Stars with Remarkable Spectra. — In Astronomische 

 Nachrichten, No. 3171, Mr. T. E. Espin continues his list of 

 stars with remarkable spectra {Astr. Nach. 3090), the number 

 amounting now to 736- The places are all brought up ap- 

 proximately to 1900. 



The Period of Rotatio.n of Venus. — It was hoped that 

 the pure telescopic observations of the surface of Venus would 

 settle the question of the period of rotation, but the results show 

 that we are not yet in possession of the absolute value as can be 

 gathered from a comparison of Schiaparelli's work with Trou- 

 velot's, and Loschardt's and Wislicenus determinations. A 

 method, apparently not yet tried, is that suggested by Egon von 

 Oppolzer {Astr. Nach. 3170), which involves the use of the 

 spectroscope for the determination of the motion in the line of 

 sight. By comparing the spectra of opposite points on the 

 equator, he says it might probably be possible to determine the 

 time of rotation. Cassini de Vico's assumption involves a 

 velocity for rn equatorial point of somewhere about 473 metres 

 per second, so that we should expect to get a motion, indicated 

 in the spectrum by the displacement of the lines, of about 946 

 metres, or roughly, one kilometre. This motion, he thinks, 

 can with our present means of measuring be made apparent, and 

 we should thus decide between Cassini de Vico's assumption 

 and Schiaparelli's 225-day period. 



The Newall Telescope. — The report of the work done 

 with the Newall refractor {Camb. Univ. Reporter, June 20) 

 shows that during the past year the work was severely handi- 

 capped by the fact that the driving clock was undergoing repair. 

 Last summer the objective prisms were adjusted, and about eighty 

 stellar spectra were obtained, sixteen of which are of use for 

 measurement ; but later the driving worm had to be dismounted 

 and sent to Dublin. Using a single prism, the spectrum beween F 

 and II is 2 inches long. In a photograph of Vega with an expo- 

 sure of nine minutes the hydrogen lines up to ^(Hiiggins's nota- 

 tion) were obtained, thespectrum between F and f being 3 inches 

 in length. With both prisms the dispersion is very great, the 



NO. 1236, VOL. 4SJ 



spectrum more than covering the length 0^ the photographic 

 plate used (length between Hy and H is 175 inches). The 

 necessity of having to send the driving worm of the new clock 

 away to be re-cut, in addition to making several instru- 

 mental tests, seems to have taken up much of the time that 

 might have been used in observing. The fifth satellite of 

 Jupiter is within the reach of this instrument, and has been seen 

 on two occasions, January 24 and February 4, Mr. Newall 

 remarking that "it has been most justly described as a very 

 difficult object." 



Johnston's Notes on Astronomt. — Under this title we 

 have before us a small book, by Swift P. Johnston, edited by 

 James Lowe, consisting of about eighty pages, dealing with the 

 more purely elementary mathematical portion of astronomy. 

 The book is a compromise between a popular work and a text- 

 book for students, and links the one to the other. Coming out 

 originally in the form of notes, the present edition has been 

 widely expanded, and may now be said to form an excellent 

 course of astronomy for beginners. It is simple-worded and 

 concise, and presents the reader with a general sketch of the 

 more important problems which is the part of the science of 

 astronomy to solve. The diagrammatical figures supplement 

 and render more clear various parts of the text, and the 150 

 excellent questions, if fully answered by the reader, would prove 

 a very serviceable addition to his astronomical education. 



The Hodgkins Fund Prizes. — The following prizes are 

 announced by the Smithsonian Institution with the intention of 

 furthering the wishes of Mr. Thomas Hodgkins, who we have 

 previously referred to as having presented a large donation to 

 the institution for the "increase and diffusion of more exact 

 knowledge in regard to the nature and properties of atmosphtric 

 air in connection with the welfare of man" : — 



(1) Slo,ooo for a treatise embodying some new and im- 

 portant discovery in regard to the nature and properties of 

 atmospheric air. These properties may be considered as bearing 

 upon all or any of the sciences, e.g. not only in regard to 

 meteorology, but in connection with hygiene, or with any de- 

 partment whatever of biological or physical science. 



(2) S2000 for a satisfactory essay on : (a) The known pro- 

 perties of atmospheric air considered in their relationship to 

 research in every department of natural science, and the im- 

 portance of a study of the atmosphere considered in view of 

 these relationships, {b) The proper direction of future research 

 in connection with the imperfections of our knowledge of at- 

 mospheric air, and of the connections of that knowledge with 

 other sciences. The essay a- a whole should tend to indicate 

 the path best calculated to lead to worthy results in connection 

 with the future administration of the Hodgkins foundation. 



(3) Siooo for the best popular treatise upon atmospheric air, 

 its properties and relationships (including those to hygiene, 

 physical and mental). This essay need not exceed 20,000 

 words in length. 



All these treatises may be written in English, French, Ger- 

 man, or Italian, and sent to the secretary of the Smithsonian 

 Institute, Washington, before July I, 1894, with the exception 

 of those in competition for the first prize, which will be delayed 

 until December 31, 1894. Further information on the above 

 and other points, such as the giving of medals, &c., may be ob- 

 tained from the secretary's report, and also hoxa. Astronomy and 

 Astrophysics, No. 116, p. 560. 



GEOGRAPHICAL NOTES. 



At the meeting of the Royal Geographical Society, held on 

 June 26, Captain F. R. Maunsellgave an account of his journeys 

 in Kurdistan during the summer of 1892. Kurdistan is not an 

 accurately-defined province, but may be described as the exten- 

 sive district inhabited by the Kurds, embracing the region of 

 Lake Van and the Upper Euphrates, as well as the country 

 between the Tigris and the Persian frontier south of Lake 

 Van. Captain Maunsell entered Kurdistan from the north, 

 passing Erzingan and Erzerum, and skirted the eastern shore 

 i)f Lake Van. The watershed between the lake and the Tigris 

 Valley is very low, but it is not easy to discover any place at 

 which there might at some former time have been an outlet. Il 

 seems not unlikely that a lava overflow from the volcano 

 Mount Nimrud, on the western shore of the lake, cut off the 

 plain of Van from the Tigris, and thus formed the lake. Captair 



