Jan. 30, 1890] 



NATURE 



305 



Name. 



(i) G.C. 1425 



(2) DM. + 17" 1479 ... 



(3) f Canis Minoris ... 



(4) y Oeminorum 



(5)78Schj 



(6) R Leonis 



Mag 



6 

 Var. 



Colour. 



Yellowish-red. 

 Yellowish-white. 



Bluish-white. 



Reddish-yellow. 



Vtry red. 



R.A. 1890.1 Decl. 1890. 



h. m. s. 



6 26 3r 



6 56 I 



7 »9 f> 

 6 31 24 

 6 28 59 

 9 41 39 



T-io 14 



+ 17 53 

 + 930 

 + 16 30 

 +3831 

 -t-ii 56 



Remarks. 



(l) This nebula is described by Sir John Ilerschel as "pretty 

 large, cometic, much brighter nucleus south following." The 

 remarks relating to the nebula G.C. 1 185 (see p. 257) apply 

 equally in this case, the spectrum not having been recorded. 

 Next in importance to observations of the general character of 

 the spectrum will be observations of differences between the 

 spectrum of the nucleus and that of the "tail." It seems hardly 

 likely that the same spectrum will be given by the dense and 

 sparse portions of the nebula. 



(2) This star has a fine spectrum of the Group II. type. 

 I >uner stales that bands 2-8 inclusive are visible, and possibly 

 also band 9, all the bands being very wide and dark. The point 

 chiefly requiring attention in a spectrum of this character is the 

 presence or absence of the compound fluting of carbon which 

 extends from about wave-length 468 to 474, it having been sug- 

 gested that band 9 is simply a contrast band due to the presence 

 of this fluting. The mean wave-length given by Duner for the 

 edge of band 9 is 476 'o, and if the suggestion referred to be of any 

 value, this ought to be coincident with the less refrangible edge 

 of the carbon group. This can only be satisfactorily settled by 

 direct comparisons of the spectrum of the star with that of 

 carbon, obtained in the usual way from a Bunsen or spirit-lamp 

 flame. 



(■?) Vogel classes this with stars of the solar type. The usual 

 differential observations are required. 



(4) A star of Group IV. (Gothard). The usual observations 

 are required (see p. 285). 



(5) This is a star of Group VI., Duner stating that the bands 

 2-9 are visible. Band 6 is a little weaker than the other carbon 

 flutings. It seems probable that some of the brighter stars of 

 the group will give metallic line absorptions, seeing that they 

 are most probably formed by the cooling of stars like the sun, in 

 which there are only traces of carbon absorption, whilst the line 

 absorption is strongly marked. If the b group be present, it 

 will most likely produce an apparent displacement of the carbon 

 fluting to a slightly less refrangible position, its absorption being 

 added to that of carbon. This can readily be determined by 

 comparison with the spirit-lamp flame. Other lines may also 

 appear, but b is mentioned as being amongst the more prominent 

 solar lines. 



(6) Mr. Espin found bright lines in the spectrum of this variable, 

 when near its maximum in 1889. The star will again be at a 

 maximum on January 30, and observers will therefore have an , 

 opportunity of making a more detailed examination of the 

 spectrum. The general spectrum is of the Group II. type. 

 Particular attention should be given to the bright carbon flutings, 

 both at maximum and for some time after, as it seems probable 

 that an increase of carbon radiation will accompany the appear- 

 ance of the bright lines of hydrogen. The star ranges from 

 about magnitude 6 at maximum to 95 at minimum, and the 

 period is 313 days. A. Fowler. 



The Total Eclipse of January i, 1889. — With a 

 summary of the observations of this eclipse, Prof. Holden 

 has come to the conclusion that coronal forms vary periodi- 

 cally, those of 1867, 1878, and 1889 being of the same form; 

 that the outer corona, terminated in branching forms, suggests 

 the presence of streams of meteorites near the sun, whilst the 

 extension of the corona along and very near the plane of the 

 ecliptic would show that such streams must have long been 

 integral parts of the solar system. The photographs taken just 

 before second and after third contact prove the corona to be, 

 without doubt, a solar appendage. Spectroscopic observations 

 indicate that the true atmosphere of the sun mny be compara- 

 tively shallow, it being conclusively shown that the length of a 

 coronal line is not always an indication of the depth of the 

 gaseous coronal atmosphere of the sun at that point. — Observa- 

 tory, January 1890. 



The Orbits of the Companions of Brooks' Comet(i889 

 v., July 6. — The four companions which accompanied this comet 



were notified as B, C, D, and E, respectively, by Prof. Barnard^ 

 of the Lick Observatory {Astr. Nacfi., 2919), the principal portion 

 being called A. Prof. Bredichin has computed, as far as possible, 

 the orbits of the companions {Astr. Nach., 2949). Taking the 

 elements given by Mr. Chandler for the principal mass A, the 

 following elements have been found for C and K ; all are 

 reduced to mean equinox 1 889*0 : — 



Elements of C's Orbit. 

 T = 1889 October I -3369 



Elements of A's Orbit. 

 T = 1889 October 2*1 112 



O t II 



u> = 344 29 20 '6 



a, = 17 52 19-0 

 i = 656-9 



= 28 2 II "6 

 log a = 0*565011 

 Period = 7 0390 years. 



« = 344 II 47-1 



a = 17 15 245 

 I = 656-2 

 <p ~ 2S 2 13-2 



log rt - 0-505059 

 Period = 7*0402 years. 



Elements of E's Orbit, i 

 T = 1889 October 8*7356 



" = 347 30 i8*9 



Si = 17 52 24-5 



« — 6 5 6*2 

 (/) = 28 10 10*5 

 log a = 0-564834 

 Period = 7*0348 years. 



The orbit of the mass B is situated between the orbits of A and 

 C, and the orbit of D between those of C and E. From the 

 inclination and position of the node it is evident that the 

 division of the comet was effected in the plane of A's orbit, and 

 the elements of C and E indicate almost the same point for the 

 separation of the comet into these masses. It may be, therefore, 

 that the separation was due to the action of Jupiter. 



Greenwich Observatory. — The Astronomer-Royal has^ 

 issued the Greenwich Observations for 1887. An additional 

 feature is the ten-year catalogue of 4059 stars, deduced from ob- 

 servations extending from 1877 to 1886, and reduced to the 

 epoch 1880. The work, therefore, appears more bulky than 

 ever. 



THE PHYSICAL AND CHEMICAL CHARAC- 

 TERISTICS OF METEORITES AS THROW- 

 ING LIGHT UPON THEIR PAST HISTORY. 



T N several articles which appeared in Nature last year I used 

 the term meteorite as a generic one, to include all meteoritic 

 masses, whether they consist of the tiniest specks which give rise 

 to the instantaneous appearance of a shooting-star in the highest 

 reaches of our air, or of the largest masses which have so far been 

 found after their descent to the earth's surface. 



I must now confine it to those masses which have reached the 

 earth's surface, whether large or small, and I have first to refer to 

 the variou-i suggestioiis which have been made as to their origin. 



The members of the Academy of Sciences of Paris were the 

 last to acknowledge their extra-terrestrial origin, and that long 

 after the writings and reasonings of Chladni, to which reference 

 has been made. 



Laplace ascribed them to lunar volcanoes,^ by others it 

 was imagined that they came from our own volcanoes ; there 

 were those, also, who held that they came from the sun ; while,, 

 again, others thought they were fragments of a broken planet. 



The theory of the volcanic origin of meteorites, whether lunar 

 or terrestrial, does not satisfactorily explain the orbital motions 

 around the sun, for, if this were their real origin, the meteorites 

 would travel round the earth. Neither does it explain the rela- 

 tions which exist between comets and meteorites, for no one 

 supposes that comets are effects of volcanic action. Further,, 

 fragments thus ejected from the earth's surface would be con- 

 sumed in the journey by the same process which is afterwards to 

 render them visible to us as shooting-stars. 



With regard to the theory of the solar origin of meteorites, it is 

 difficult to understand how solid bodies can come from the sun 

 after passing through an immense thickness of the intensely heated 

 solar atmosphere. Then, again, particles shot out from the sun 

 would not travel in an orbit, as the meteorites do, but would 

 simply move outwards in a straight line, and then fall back. 



That the meteorites are fragments of a broken planet is sup- 

 ported by a considerable number of facts, but the main difficulty 



' " Les l^etcorites," Meunier, p. 112. 



