April IS, 1875] 



NATURE 



473 



local time, and the duration is about im. i8s. The cen- 

 tral eclipse begins in longitude 1 16°'6 W., latitude 18° N. ; 

 it takes place with the sun on the meridian in 44°'8 W. 

 and 44"'9 N., and passes off the earth in 3i°-8 E. and 

 25°'4 N. At Greenwich the magnitude of this eclipse 

 will be less than o'j. 



Winnecke's Comet. — In Nature, vol. xi. p. 349, it 

 was stated that the identity of this comet with that found 

 by Pons at Marseilles, 1S08, February 6, a.m., suspected 

 by Prof. Oppolzer, is open to doubt. There is contradic- 

 tion in the only two accounts of this comet which we 

 possess. In the first one, which will be found in Zach's 

 Monat. Corrcsp. xviii., it is described as " very small ; " 

 the discover)' was not made known to the astronomical 

 public, partly because no regular observations were pro- 

 cured, and the strong moonlight prevented its being seen 

 after the morning of Feb. 9. Schumacher having inquired 

 of Pons whether amongst his papers some more definite 

 account of this comet were to be found, received from 

 him, through Inghirami, a communication which was 

 printed (apparently long after its receipt) in Astron. Nach. 

 vii., c. 113. Pons says the comet was one of those of 

 which it was not possible to calculate the elements, be- 

 cause there were only procured jsome very doubtful posi- 

 tions by reference to nebulre in the vicinity. He adds : 

 " El!e dtait tr^s-faible et difficile ^ voir. Sa nebulosity 

 ^tait ronde ; elle s'etendait il peu prfes un ddgrd et on y 

 soupconnait par intervalle un tris-faible noyau en deux 

 parties. Son mouvement ^tait assez rapid vers le sud. . . ." 

 He then gives a sketch showing the configuration of 

 the comet and two nebute, in a telescope with a field of 

 nearly 3°. The nebulas he describes as " sur le ventre 

 d'Ophiuchus un peu au dessous de I'Equateur;" and 

 Oppolzer identifies them with Nos. 10 and 12 of Messier's 

 Catalogue. Hence we have an approximate place of the 

 comet for Feb. 9 (at 5 a.m. at Marseilles), and Pons tells 

 us it was moving pretty rapidly towards the south. If we 

 now adopt Clausen's elements of Winnecke's Comet for 

 1819 (obtained by connecting the observations of that 

 year with those of 1858, by calculation of the perturba- 

 tions), and assume the date of perihelion passage in 1808 

 with Oppolzer on April i2'o, we have the following geo- 

 centric places : — 



R.A. 



1 Feb. 5.16 Marseilles 237 56 

 6.17 ,, 239 10 



8-17 ., 241 39 



N.P.D. Distance 

 o f from Earth. 



97 o I 044 

 97 10 I 031 

 97 31 I -007 



These positions do not indicate what could be termed 

 a pretty rapid motion towards the south, and at a 

 distance exceeding the mean distance of the earth 

 from the sun it is very unlikely that a comet would 

 present an apparent diameter approaching one degree. 

 So far as can be judged from Pons's communication 

 to Schumacher, we may rather infer that the object 

 he observed was very near to the earth. Clausen's 

 elements of Winnecke's Comet in 18 19 show that it was 

 then moving in an elhpse with a period of 2031 '8 days : 

 two such periods reckoned backward from the date of 

 perihelion passage in 1819 would bring us to 1808, June 

 2'5, instead of April 12. It does not, therefore, appear 

 that sufficient grounds exist for supposing the comet of 

 February 1808 to have been identical with the one which 

 now bears Prof. Winnecke's name. We may take this 

 opportunity of stating that according to Clausen's calcu- 

 lation of the perturbations, Winnecke's Comet was in 

 J)erihelion on the following dates between the appear- 

 ances in i8i9and 1858, passing unobserved in each year : 

 1825, Feb. 55, G.M.T. ; 1830, Aug. 21-4; 1836, March 

 3'4 ; 1841, Sept. I3'9 ; 1847, March 29'o ; and 1852, 

 Oct. 117. 



The Star B. A. C. 2695.— This sixth-magnitude star of 

 the British Association Catalogue was missed in August last 

 by Mr. Tebbutt, of Windsor, N.S.W., being then invisible 



in a telescope of 4^ inches aperture. It is No. 1871 of 

 the Paramatta Catalogue, where the place depends upon 

 a single complete observation, the magnitude attributed 

 to the star being 6. It is also No. 966 of the catalogue in 

 the fifth volume of Taylor's Madras Observations, the 

 position depending upon two observations in each element 

 in 1S38 or 1S39, but the recorded magnitude is 10. So 

 great a difference in the estimated brightness clearly 

 points to variability, which is confirmed by Mr. Tebbutl's 

 recent notice. The position for the beginning of 1875 's in 

 R.A., 7h. 57m. 30s., N.P.D. 150" 9'7 ; five minutes distant 

 from this star, on an angle of 180°, is the sixth magnitude 

 B.AC. 2694, which Mr. Tebbutt found " decidedly red." 

 It may be remarked that the ffth volume of Taylor's 

 Madras Observations, to which reference is made above, 

 is b)- far the most valuable of his series to the astronomer 

 in the southern hemisphere ; but it is not, we believe, now 

 easily procured. 



THE "TIMES" WEATHER CHART 

 "|\ /["ANY of our readers will have noticed the unusual 

 -'■'-'■ appearance of illustrations in the Times in the shape 

 of the small charts which have been appended to the 

 Daily Weather Reports since the ist inst. This measure 

 has been the long-postponed carrying out of the line of 

 action indicated by the Meteorological Committee in their 

 Report for last year, and the chart in its present form 

 differs but little from that printed as a specimen in that 

 Report. We subjoin the chart for the 13th inst., 8 a.m., 

 )iuUished in yesterday's Times. 





The dotted hnes indicate the gradations of barometrical pressure, the figures 

 at the end showing the height, with the words " Rising," " Falling," i*{;c. , 

 as required. The temperature at the principal stations is marked by 

 figures, the state of the sea and sky by words. The direction and force 

 of the wind are shown by arrows, barbed and feathered according to its 

 force. © denotes calm. 



The method of preparation of the chart seems simple 

 enough at present, but it has been the fruit of much 

 thought, as the problem of producing, in the space of an 

 hour, a stereotype fit for use in a Walter machine has 

 not been solved without many and troublesome experi- 

 ments. 



I 



