194 SCIENTIFIC RECORD FOR 1884. 



are a reflector of 20 inches aperture ; a reflector of 13 inches aperture ; 

 a Thollou spectroscope, giving the dispersion of 31 flint prisms; a small 

 meridian circle; spectroscopes; apparatus for solar photography. An 

 account of this observatory is given in Bulletin Astronomique April, 1884. 



Australian observatories. — The eighteenth annual report of the director 

 of the observatory at Melbourne has been issued. The new transit- 

 circle was expected in a short time, and would find the new circle-room 

 ready to receive it, but the instrument which had been in use for twenty 

 years continued to give excellent and trustworthy results ; nevertheless, 

 each year had forced upon Mr. Ellery the necessity of greater optical 

 scope for the meridian work. The inevitable loss of reflective power in 

 the great telescope increases a Jitile year by year, but does not yet 

 sensibly affect the work upon which it is employed. Indeed, Mr. Ellery 

 says, "some photographs of faint objects obtained lately are clear evi- 

 dence of the immense light-gathering power it still possesses, and of 

 the trivial loss occasioned so far by the slight tarnish apparent." The 

 instrument had not been kept quite so closely to its special work — the 

 revision of the southern nebulae — as before, owing to the number of 

 nights occupied with the great comet^ and in experimenting in celestial 

 photography. Among the subjects of observation Mr. Ellery refers to 

 the transit of Venus, the Port Darwin Expedition for determination of 

 longitude of Australian observatories, and measures of diflerences of 

 declination of the minor planets Sappho and Victoria for determination 

 of the solar parallax, according to the scheme arranged by Mr. Gill. 

 The great comet of 1882 was kept in view for 250 days, or until April 

 26, 1883. A large portion of the work connected with the telegraphic 

 determination of the longitude of Australian observatories from Green- 

 wich fell upon the Melbourne establishment, which is now assumed to 

 be in longitude 9^ 39"" 53^.37 E., subject, perhaps, to some very small 

 correction. As soon as the new transit-circle was properly adjusted, 

 it was Mr. EUery's intention to devote it to the revision of a rather large 

 catalogue of stars, at the request of the Astronomische Gesellschaft, 

 besides its more special work. The great telescope would be applied 

 more exclusively to the continuation of the revision of Sir John Her- 

 schel's uebulije, several of which, by the way, the Melbourne observers 

 have not been able to find. {Nature.) 



Observatory of Natal. — From a late issue of Science we learn of astro- 

 nomical work now going on at Natal, under the direction of Mr. Edmund 

 Keisou, Government astronomer at that place. The following subjects 

 are being pursued : 



1. " The determination of the exact amount of parallactic inequality of 

 the motion of the Moon by means of observations of the positions'of a 

 crater near the center of the lunar surface. 



2. " The determination of the exact diameter of the 31oon by observa- 

 tions of pairs of points near the limb, 



