Nov. 14, 1889] 



NATURE 



45 



is a faint continuous spectrum at the preceding edge of No. 386. 

 The point chiefly requiring attention at present is the character 

 of the line near 500. Many recorded observations describe this 

 line as having a fringe of light on the more refrangible side, 

 whilst others state that it is perfectly sharp on both edges. Low 

 dispersion only should be employed in making this observation. 

 The observation of continuous spectrum in a special part of the 

 nebula 386 is also worthy of attention ; the spectrum should be 

 examined for maxima of brightness, as in the case of the nebula 

 in Andromeda. 



(2) Duncr records this as a star of Group II. (see below), but 

 states that the spectrum is very feebly developed. The star is 

 probably, therefore, either just condensing into a fully-deveioped 

 star of Group II., or is just passing into Group III. If the 

 former, there will practically be nothing but very narrow bands, 

 and if the latter, absorption lines will accompany the bands. In 

 the earlier stages of this group, the bands in the blue are 

 strongest, whilst in the later stages red bands are strongest, 

 and this point should also receive attention. As a check, the 

 colour of the star should be noted at the time of observation. 



(3) This star belongs to either Group III. or to Group V., 

 and the criteria (see p. 20) should be observed in order to 

 determine which. 



(4) According to Vogel, the spectrum of this star is of the 

 same type as a Lyrge, i.e. Group IV. The relative intensities of 

 the metallic lines and those of hydrogen, which vary from star 

 to star, should be noted for future classification of the stars of 

 this group according to temperature. 



(5) This is a star of Group VI. Duner describes the spectrum 

 as consisting of four zones, the zones being the bright spaces 

 between the dark carbon flutings. The presence of slight traces 

 of carbon absorption in the solar spectrum indicates that stars of 

 this group only differ in temperature from stars like the sun. 

 The passage from one group to the other will probably be found 

 to be very gradual, and the widths of the carbon flutings and 

 the presence or absence of other absorptions should therefore be 

 noted. 



(6) Period given by Gore as 382 days, and magnitude at 

 maximum (November 13) as 6 "9-7 7. The spectrum has not 

 yet been recorded, and the present maximum may, therefore, 

 conveniently be taken advantage of. 



(7) Period given by Gore as 168 days, and magnitude at 

 maximum (November 15) as 8*3-9. Spectrum not yet recorded. 



iVi;/^.— -Lockyer's classification will, in future, be exclusively 

 used, so that there will be no necessity for a double reference. 

 The relation of this to Vogel's classification is shown in the 

 following diagram : — 



Group IV. (Cl.^ss \.d). 



Group III. 

 (Class 1 1, a). 



Group 1 1. 

 (Class Ill.a) 



Group I. 

 (Classes I a 

 and W.b, and 



nebulae). 



Group V. 

 (Class 11. a). 



Group VI. 

 (Class HI./') 



Group VII. 



Lockyer's Temperature Curve. 



The temperature increases from Group I. to Group IV., and 

 then decreases to Group V, On the ascending side of the 

 "temperature curve" we have probably to deal with con- 

 densing meteoritic swarms ; and, on the descending side, with 

 gradually condensing masses of meteoritic vapours. 



A. Fowler. 



Large- Scale Charts of the Constellations. — Mr. 

 Arthur Cottam has projected a series of thirty-six most excellent 

 charts of the constellations from the North Pole to between 35° 

 and 40° of south declination, and showing stars in half mag- 

 nitudes down to 6i by disks of various sizes. Although the 

 primary object in constructing these charts was to make them 

 companions to Webb's "Celestial Objects for Common Tele- 

 scopes" and Smyth's "Cycle of Celestial Objects," their scope 

 has been considerably enlarged, and a number of double, mul- 

 tiple, and variable stars have been laid down which are not 

 included in either of the above-mentioned works. The Earl of 

 Crawford's (Dun Echt) sununaiy of F. G, W. Struve's Dorpat 



Catalc^ue included 2248 double and multiple stars, and of them, 

 2130 are shown upon these charts. In addition to this, 275 of 

 the double stars discovered by Mr. S. W. Burnham have been 

 mapped, this being the whole of those included in his first four 

 catalogues, and a selection from his other catalogues. The maps 

 have been drawn to a scale of one-third of an inch to a degree, 

 which is a much larger scale than any hitherto published, and 

 as each map includes but a small portion of the heavens, there 

 is practically no distortion, whilst the epoch being 1890, 

 the positions will hold good, without any serious errors, for 

 fifteen or twenty years beyond that date. The projection is 

 conical, or, in those charts which extend any distance both north 

 and south of the equator, cylindrical. Hence it will be easy to 

 lay down any additional objects that may be required. There 

 is no doubt that these charts will be eminently useful, one of 

 their great advantages being that they will enable possessors of 

 telescopes mounted on altazimuth stands or without circles to 

 find with ease a large number of interesting objects, and thus 

 will help to extend the knowledge of the heavenly bodies and to 

 popularize the most fascinating of sciences. We may say that 

 the publisher of these charts is Edward Stanford, Cockspur 

 Street, S. VV., and that the first issue is limited to 200 sets, 

 many of which have been already subscribed for. 



Barnard's Comet, II. 1889, March 31. — The following 

 ephemeris is given in Astronomisclie Nachricklen, No, 2931 : — 



18S9. 



Nov. 6 .. 

 7 ■• 

 8.. 



9.- 



10 .. 



11 .. 



12 .. 



13 •• 



14.. 



15 •• 



16.. 



17.. 

 18., 

 19.. 



20 ., 



21 . 



22 . 



R.A. 

 h. m. s. 

 I 854 



5 49 

 249 



05953 



• 57 I 



■ 54 13 



51 29 



DecL 



o / 



- 16 30-2 



-1637-2 



— 16 43 6 



- 16 49-5 



- 16 54-9 

 -1659-8 

 -17 4-1 



4850 ... -17 8-1 



Dec. 



46 15 ... - 17 II-6 



43 44 ••• -17 14-8 



41 17 ... -17 17-4 



3855 ... -17 197 



3636 ... -17 21-5 



34 21 ... - 17 22*9 

 32 II ... - 17 24"0 

 30 5 ... -17249 



28 2 ... -17 25-4 



The Structure of Jupiter's Belt 3, III. — This dark 

 band appears under ordinary conditions to be made up of two 

 parallel bands, but Dr. Terby {Astroiioniische Nacliricliten, No. 

 2928) says this appearance of parallelism is the result of the 

 special structure represented in the accompanying figure, and 



Nov. 22 , 



23. 



24. 



2^ . 



26, 



27. 



28. 



29, 



30. 

 I 



2 . 

 3. 

 4. 

 5' 

 6 



7 



2 ... 

 3-- 



R.A. 

 h. m. s. 

 ,028 

 , 26 



24 «... 



22 17 ... 



20 29 .. 



I8 45-. 

 , 17 5- 

 . 15 28 .. 



• I3 55-- 

 12 25 ... 

 1058... 



9 34--- 

 . 813... 

 . 656... 



■ 5 4I-- 

 429... 

 320... 



Decl. 



- 17 2S-4 

 -1725 7 

 -1725-6 



- 17 25'2 



- 17 247 

 -17 23-9 



- 17 228 



- 17 2r6 



- 17 20-0 



-17 18-3 

 -17 16-3 

 -17 i4"3 



- 17 12"0 



-17 97 

 -17 7-1 



4 '4 

 15 



•17 

 17 



Structure of Jupiter, 

 that, therefore, the band 3, III., is composed of a lot of dark 

 bands inclined in the same direction. The circular parts A are 

 distinguished by Dr. Terby as emitting a sort of diffused light of 

 an entirely different character from the white equatorial spots, 

 properly so called ; these luminous balls seem always to occur at 

 the interval between two of the inclined bands, and touching 

 what is generally their darkest part, B. The brilliant white 

 spots D also appear at the dissolution of two successive bands, 

 and occupy by preference their northern extremities. When the 

 definition was very good. Dr. Terby observed that the interval 

 between two of these fragmentary bands had the appearance 

 of a series of globules, as shown in the figure. The structure 

 appears so general and regular that it may be the means of 

 adding considerably to our knowledge of the physical constitution 

 of this planet. 



GEOGRAPHICAL NOTES. 



At the first meeting of the session of the Royal Geographical 

 Society, the paper was on Cyprus, by Lieut. -General Sir Robert 

 Biddulph, G.C.M.G., C.B. The island of Cyprus is the third 

 largest in the Mediterranean, being inferior in size only to Sicily 

 and Sardinia. Its area is 3584 square miles. Its principal 



