244 



NATURE 



[Jan. II, 1877 



viz. loh. l6m. o*4s. Doubt has been occasionally expressed 

 with regard to Sir W. Herschel's rotation-period from the uncer- 

 tainty attaching to such obser-valions, and the interesting confir- 

 mation of it just arrived at by the American observers vi^ill 

 therefore be the more v^elcome. The Herschelian rotation for the 

 planet globe of Saturn has been sometimes confounded with a ro- 

 tation not depending upon observations, but calculated on Kepler's 

 law for a satellite at an apparent mean distance equal to the 

 semi-diameter of the middle of the ring ; thus, Baily, in his 

 "Astronomical Tables and Formulae" — which were widely 

 quoted lor many years — has loh. 29m. 17s. for time of rotation 

 both of the globe and the ring.] 



The Nebula in the Pleiades. —Mr. Maxwell Hall, of 

 Jamaica, communicates some observations of this nebula made on 

 October 20, 1876, with a 4-inch Cooke equatorial, and power 

 55. "Ttie nebula was 'bright,' according to Sir John 

 Herschel's icale, and extended in a parabolical form at least 40/ 

 from Merope, which was at the focus, while the axis of the figure 

 was nearly S. of that star." 



The difficulty of seeing with very large instruments a very faint 

 nebulosity in close pioximity to a bright star is strikingly illus- 

 trated by a remark made by Mr. Dreyer, observing with Lord 

 Rosse ; he states — " The Merope-nebula is never perceived with 

 Lord Rosse's telescopes." So also D' Arrest sought for it in vain 

 with the Copenhagen refractor, subsequently referring it to the 

 class of which we are writing, which may be invisible in a great 

 telescope but seen without difficulty in the finder. Vols. Iviii- 

 and lix. of Astronomische Nachrichten may be consulted for the 

 earlier discussions as to the variability oi this object. 



Variable Stars. — Prof, Schonfeld has published in Vier- 

 teljahrsschift der astronomischen Gesellschaft, xi. Jahrgang, 

 Heft 4, an ephemeris of the maxima and minima of most of the 

 variable stars for 1877, including Algol, A Tauri, S Cancri, 

 S Librse, and U Coronse Borealis, which have short periods. 

 The max. of x Cygni is dated February 6, and the min. on 

 September 15 ; Mira Ceti, min. on July 23, max. on Novem- 

 ber 10. 



Schmidt's star in Cygnus was red on January 7, and about 

 equal in brightness to the star + 41° No. 4243 in the " Durch- 

 musterung," but the difTerence of onlyO"5m. between thecatalogue 

 brightness of this star and that of + 42° No. 4204, certainly did 

 not represent their relative intensity of light on this evening. 

 The variable might be estimated at 7"2m, by reference to the 

 latter star. 



Meteors of January 7. — In the early part of this night a 

 number of meteors were remarked near London, with unusually 

 slow motion, particularly in the cases of several which equalled 

 Jupiter in brightness. One at loh. 32m. G.M.T. starting from 

 near A and fi. Ursse Majoris, appeared to receive a sudden check, 

 and was stationary for two seconds 3° below a Canum Venati- 

 corum, where it was nearly extinguished, but a faint portion left 

 a train for several degrees further. It was not easy to judge of 

 the radiant point owing to continual interruption from passing 

 clouds, but it would probably be somewhere about the stars in 

 Ursa Major above-named. Much lightning on this evening. 

 The zodiacal light well seen as far as the principal stars of 

 Aries. 



The Melbourne Observatory. — The Eleventh Report of 

 the Board of Visitors of the Melbourne Observatory, with Mr. 

 EUery's Annual Report for the year ended 1876, June 20, has 

 been received. In addition to the large reflectors, the Observa- 

 tory now possesses an 8-inch equatorial, both instruments in ex- 

 cellent working order. With respect to the former, Mr. 

 Ellery remarks that, although at present the mirrors retain their 

 high reflecting polish exceedingly well, it is not to be overlooked 

 that the time must arrive when they will require to be re- 



polishtd, n.rid in anticipation of this eventuality, which may 

 occur sooner than is now looked for, he intends to devote time 

 during the ensuing year to practice in grinding and polishing 

 large surfaces. Out of about 150 nights duiing the year to 

 which the report applie.-, which were more or less fit for observ- 

 ing with the reflector, forty were solely occupied with visitors. 

 The astronomical work accomplished includes the examination, 

 measurement, and sketching of seventy of the nebulae and 

 clusters of Sir John Herschel's southern work, of which the 

 greater number have been drawn and described in a manner 

 suitable for publication. Mr. Ellery adds: — "The result of 

 these observations indicates that several of the nebuloe are con- 

 siderably changed, while others appear so completely altered as 

 to be scarcely recognisable, save by their position with respect 

 to adjacent stars. The nebula about tj Argus have bten com- 

 pared with a drawing made in March, 1875, but no decided 

 changes were detected. The weather was so far unfavourable 

 at Melbourne for certain classes of observations that out of ninety 

 conjunctions of Saturn's satellites only ten could be observed. 

 No material change in the regular work of the Observatory is con- 

 templated during the year following the conclusion of the report. 

 Observations with the transit-circle v/ould be continued a.-isidu- 

 ously as in previous years, the Government Astronomer regard- 

 ing this as the fundamental work of the establishment, which 

 has already given it a reputation in the world, and he quotes in 

 proof of this the opinion expressed by Sir George Airy, that 

 the Melbourne Observatory had produced " the best catalogue of 

 stars of the southern hemisphere ever published." The revision 

 of Sir John Herschel's figured nebulae will also be continued, 

 with occasional planetary work, as drawings of Mars and Jupiter, 

 observations of conjunctions of Saturn's satellites, &c. 



The early publication of results obtained with the great re- 

 flector is strongly urged by Mr. Ellery, and all astronomers will 

 concur in his representations upon this point. Difficulties, no 

 doubt, must exist in giving such results to the astronomical 

 world in a perfectly satisfactory manner ; nevertheless, Mr. 

 Ellery thinks if a plan he proposes is approved, these difficulties 

 may be surmounted, and all the completed work with the re- 

 flector may be forthwith published. We can only express the 

 hope that work of such great interest, and which may so greatly 

 add to the reputation of the Melbourne Observatory, will soon 

 be in the hands of the public. The importance of early publi- 

 cations of astronomical work in these days can hardly be 

 exaggerated. 



METEOROLOGICAL NOTES 

 New Daily Weather Map. — We hail with the greatest 

 satisfaction the appearance, on New Year's Day, of the first 

 number of a daily international weather-map issued by the Aus- 

 trian Meteorological Institute. It embraces nearly the whole of 

 Europe, and supplies a want not met by any existing weather- 

 maps, in representing the weather of Central and part of Southern 

 Europe, with a satisfactory fulness such as the meteorology of 

 this important region demands in the development of this branch 

 of the science. In addition to the invaluable material this pub- 

 lication will lay before us from day to day relating to thunder- 

 storms, the summer rains, and the falls of hail and snow of Cen- 

 tral Europe, it will also furnish data absolutely indispensable in 

 investigating the causes which determine the course and the rate 

 of progress of the storms of North-western Europe. Indeed, 

 in this respect, and consequently in the prognosis of British 

 storms, the Austrian empire is, of all countries which lie east- 

 wards of Great Britain, second in importance only to Lapland 

 and the north of Scandinavia. 



Low Temperatures. — During recent weeks some remark- 

 ably low temperatures have been recorded in various countries. 

 During a heavy storm which occurred on December 17 over 



J 



