520 



NATURE 



{Sept. 12, \%^Z 



of Jupiter, its colour being green (very similar to that of burning 

 silver), suddenly changing to a dull red on falling to pieces at 

 the end of its course. 



The meteor appeared at about R.A. i8h. lom., Decl. S. io% 

 and travelled slowly till it broke up in R.A. I7h. om., Decl. S. i6° 

 (or nearly coinciding with the star 77 Ophmchi), being visible 

 for about three seconds. Sydney Evershed 



Wonersh, Guildford, September 4 



OUR ASTRONOMICAL COLUMN 



The Intra-Mercurial Planet.— The correction 

 applied by Prof. Watson to his first position of the sup- 

 posed intra-Mercurial planet from more complete reduc- 

 tion of his observation brings the object somewhat nearer 

 to the ecliptic, the longitude being 124° 46' and the latitude 

 ©''SI'S., at loh. 24m. 49s. G.M.T. on July 29. Close 

 and continued search along the ecliptic with large re- 

 fractors, provided with long "dew-caps" blackened 

 inside, for 10° or 12° on each side of the sun, may now 

 afford the best chance of recovering the planet previous 

 to the next total solar eclipse, or probably until the 

 eclipse in May, 1882 ; for it will be seen that in the eclipse 

 of January, 1880, the duration of totality is short, and, 

 which is of still more consequence, the central line runs 

 mainly amongst the Pacific Islands without touching any, 

 where observations would be likely to be very practicable. 

 With respect to the precautions that may be usefully 

 adopted in a search for the planet, the reader may consult 

 the remarks of Prof. Julius Schmidt in Astron. Nach., 

 878, bearing upon his daylight observations of the great 

 comet of Klinkerfues in 1853. 



Variable Stars.— Prof. Schmidt notes the variability 

 of the star Lalande 46090, rated 6m. in the catalogues of 

 Argelander and Heis, but which was invisible without the 

 telescope on July 9 and 10, 1878. It is 7m. in Bessel, 

 and only 8*9 in Lamont. The position for 1880 is in 

 R.A. 23h. 26m. I2S., N.P.D. 101° 39'-6. 



The Athens observations, last May and June, establish 

 a material increase in the period of the well-known 

 variable 8 Librae. The error of Schonfeld's ephemeris 

 in May, 1877, was — 32m. ; in the present year it was — 48m., 

 from the naked-eye observations, considered preferable 

 to those made with the comet-seeker. ^ Cygni was at a 

 maximum (hardly 5m.) on March 14, 1878, 4o8"6 days 

 having elapsed since the preceding maximum. Prof. 

 Schmidt refers to a star in the nebula of Orion, No. 822, 

 of Bond, which exhibited marked change of brightness in 

 April last, having been seen as faint as 12 8 and as bright 

 as 97. This star follows B, 34'3s., and is south of it S''i. 

 In previous years he had not noticed any sensible differ- 

 ence between No. 822 and No. 784, which precedes 8 •5s. 

 and o'"3 to the north. 



Mr. Tebbutt writes from Windsor, N.S.W., with re- 

 erence to our notice of his newly-discovered variable in 

 Ara, that in his communication to the Astron. Nach. the 

 field of view should have been given as about half, in- 

 stead of three-fourths of a degree. Although Brisbane 

 6,142, is still visible as a star of the eighth magnitude, 

 6,183 of the same catalogue cannot now be found; but 

 an error of two minutes in the observed R.A. will identify 

 it with 6,196, exactly on the same declination. — Prof. 

 Bickcrton, of Canterbury, N.Z., sends us an outline of a 

 lecture delivered by him at the Philosophical Institute of 

 this place, on the explanation of the phenomena of 

 variable stars. Amateurs in such latitudes may do ex- 

 cellent service, with comparatively little expense of time, 

 and with very small optical means, in furthering our 

 knowledge of the variable stars of the southern heavens, 

 providing themselves for the present with Behrmann's 

 Atlas, the magnitudes in which are recorded from recent 

 observations ; while at no distant time it may be expected 

 the charts of the Cordoba Uranometria, prepared under 

 much greater advantages, will be available to them. The 



popular atlases are useless in such investigation. We 

 hope the result of attention being directed to subjects of 

 this nature at the Antipodes may be to greatly increase 

 the number of observers in departments of practical 

 astronomy, peculiarly within the scope of the amateur, as, 

 compared with what is now to be effected with limited 

 means and appliances in the northern hemisphere, a 

 promising field is open to them. 



Swift's Comet of July 7. — Elements of the comet 

 discovered by Mr. Lewis Swift, of Rochester, N.Y., on 

 the morning of July 7, have been calculated by Dr. 

 Holetschek, from observations to July 23, made at Clin- 

 ton by Prof. Peters ; they do not resemble those of any 

 comet previously computed. The failure to observe this 

 object in Europe, though it was closely sought after at 

 several observatories, appears to have arisen from an 

 error in the telegram, which stated its motion to be slow, 

 whereas it was pretty rapid towards the south-west 

 horizon. It might hare been well observed during June, 

 the position at the beginning of the month being in the 

 vicinity of ^ Cygni, and on June 21 just south of 13 

 Lyrae. The elements are in Astron. Nach., No. 2,213. 



The Saturnian Satellite Mimas. — The series of 

 observations of the satellites of Saturn, in 1877, made 

 with the great refractor at Washington, includes but few 

 of the closest satellite Mimas, which, indeed, has not 

 been frequently observed of late years. A combination 

 of the later Washington measures, with observations 

 made by Mr. Lassell in 1847, and a few intermediate 

 ones, indicates, on the assumption of a circular orbit in 

 the plane of the ring, a period of 22h. 37m. 6'82s., but 

 there appear grounds for suspecting a very slow increase in 

 the length of the period. Madler, from his reduction of the 

 observations of Sir W. Herschel, considered a very sen- 

 sible eccentricity was shown by them, which more recent 

 observations support. In the case of Hyperion, the per- 

 turbations as indicated by the measures must be very 

 large, but we believe Mr. Marth has found the same 

 result some time since from his investigations on the 

 theory of the satellites, the chief disturber being, of 

 course, Titan. 



GEOGRAPHICAL NOTES 



We have received three new maps of Cyprus. The 

 first, to which we have already brieiiy referred, is by the 

 well-known German geographer. Dr. Kiepert, and is a 

 valuable original compilation based upon the English 

 Admiralty chart, but containing many more names of 

 villages, &c., than any other modern map. A noticeable 

 point of this map is the hill-work, which has been very 

 artistically rendered. Stanford's Cyprus is also an 

 original work, with some useful features not found in 

 Kiepert' s. The Kaimakamliks and Kazas are all dis- 

 tinctly bounded and named, and although there are not 

 so many names as in Kiepert' s map, yet those that find a 

 place appear to have been judiciously selected. The 

 spaces around the map are utilised by the insertion of 

 supplementary maps presenting the agricultural and geo- 

 logical conditions, a section showing the interdependence 

 of these conditions and plans of the chief coast towns 

 and roadsteads. Wyld's Cyprus is on exactly the same 

 scale as Mas Latrie and the Admiralty chart, and appears 

 to be a combination of these two. We notice in one or 

 two places where the positions of villages do not agree in 

 these two authorities, that both positions are inserted on 

 Wyld's map, as though there were two places of the same 

 name. The hills on this map are inferior to Kiepert's ; 

 there are few English lithographers that can equal the 

 German in this art. This map, like Stanford's, intro- 

 duces agricultural and geological insets, and plans of 

 the chief roadsteads and coast towns. We need not 



