236 



NA TURE 



\yan. 7, 1886 



construction of particular tables for each satellite. The Valz 

 Prize has been awarded to Dr. Sporer for his researches on sun- 

 spots, — his discovery of the striking relationship between tbe 

 distribution of the spots in latitude and the epochs of their 

 maxima and minima receiving especial notice. 



Fabry's Comet. — The following ephemeris from elements 

 he has recently computed is given by Dr. S. Oppenheim in the 

 Astr. Nach., No. 2702 : — 



Ephemeris for Berlin Midnight 

 App. R A. App. Dec]. Log- ii 



Jan. 



23 36 IS ■ 

 35 o 

 33 35 

 32 i6 

 31 4 



12 5t 



29 19 

 38 54 

 49 23 



Barnard's Comet. — Dr. J. von Hepperger has compute<l 

 the following parabolic and elliptic elements for this comet : — 



0-2478 

 0-2514 

 o'2543 



Log. r 



0-2523 , 



0-2382 



0-2236 



Bright- 

 . 1-40 



• 1-47 

 ■ 1-55 



log? 

 log a 



Parabola 

 1886 May 6-2586 



118 57 9-9 

 67 42 522 

 87 24 30-0 

 9695574 



Ellipse 

 1SS6 May 4-5165 



121 41 24-9 



68 37 19-7 



82 51 6-2 



9-665966 



I '336444 



9-990625 



Error of the middle place (o 



- 2-4 



- 3'9 



Jk = + 48 

 <« = + 1-9 



The following ephemeris is by Dr. A. Krueger : — 

 Ephemeris for Berlin Midnight 



ASTRONOMICAL PHENOMENA FOR THE 



WEEK 1886 JANUARY 10-16 

 (For the reckoning of time the civil day, commencing at 

 Greenwich mean midnight, counting the hours on to 24, is here 

 ■employed.) 



At Greenwieh on jfanuary 10 

 Sun rises, 8h. 5m. ; souths, I2h. 7m. 51-is. ; sets, i6h. iim. ; 

 decl. on meridian, 21° 55' S. : .Sidereal Time at Sunset, 

 23h. 31m. 

 Moon (at First Quarter on Jan. 13) rises, loh. 17m. ; souths, 

 I5h. 56m. ; sets, 2lh. 45m. ; decl. on meridian, 4° 41' S. 



le at Greenwich. Attention may be drawn to the Occultations 

 1 the evening of January 16, and especially to that of Aldebaran. 



h. 



12 ... Saturn in conjunction with /i Geminorum and 

 less than i' north of that star. 



— ... Venus at her point of greatest evening bril- 

 liancy. 



Variable-Stars 



U Cephei 

 Algol 



T Monocerotis 

 s," Geminorum 

 U Monocerotis 

 5 Ubr£e 



U Coronte ... 

 U Ophiuchi... 



R LyriE 

 7) Aquila: 

 5 Cephei 



52-2 . 

 0-8 



Decl. 



8°i 16 N. 

 40 31 N. 



Jan. 



13, o 24 m 



14, 2 22 ;;/ 

 16, 23 II m 



Meteor Showers 



The cloudy weather generally prevailing at this season of the 

 year greatly interferes with meteor-observation, but a number of 

 fairly active radiants h:ive been observed, the following amongst 

 others : — From the constellation of the Lynx, R.A. 104°, Decl. 

 53° N. ; from Coma Beren, R.A. r8l°, Decl. 35° N. ; from 

 near x Cygni, R.A. 295°, Decl. 53° N. Large meteors should 

 be looked for on January 15, 16, and 17. 



STANDARDS OF WHITE LIGHT' 

 'T'lIE experimental work of the Committee during the past 

 -*- ye.ar has not been extensive, as they had no funds at their 

 disposal for experimental research, and they have been chiefly 

 occupied with reviewing what has been done in the past and 

 laying plans for future operations. 



Lord Rayleigh has constructed an instrument which he calls 

 a monochromatic telescope, by means of which the illuminated 

 screens of a photometer may be examined, allowing light only 

 of one definite colour to pass. It was hoped by Lord Rayleigh 

 that experiment might show that, with some suitably-chosen 

 colour, this instrument, used with any ordinary photometer, 

 would, in comparing lights of different intensities and tempera- 

 tures, give to each a candle-power which would be sufficiently 

 accurate to represent for commercial purposes the intensity of 

 the light. The Secretary has made some experiments at the 

 .Society of Arts, where he was kindly permitted to use the 

 secondary batteries and glow-lamps ; but the results so far are 

 not definite enough to justify their publication. 



Mr. Vernon Harcourt has been engaged on an investigation 

 on the barometrical correction to his pentane standard, .and on 

 another concerning the possibility of using lamp-shades as a 

 protection from air-currents. His researches are communicated 

 independently to the meeting. 



Capt. Ahney and Col. Festing have continued their observa- 

 tions on the intensity of radiations of different wave-lengths 

 from incandescent carbon and platinum filaments at different 



^ Report of the Committee, consisting of Prof. G- Forbes, Capt. Abney, 

 Dr. J. Hopkinson, Prof. W. G. Adams, Prof. G. C. Foster, Lord Rayleigh, 

 Mr. Preece, Prof Schuster, Prof. Dewar, Mr. A. Vernon Harcourt, and 

 Prof, .\yrton, appointed fir the purpose nf reporting on Standards of White 

 Light. Drawn up by Pr f. G. Forbes (.Secretary). 



