ASTRONOMY. 419 



taut well-defined object is reflected down the tube of the telescope. 

 The object-glass of the telescope having previously been stopped down 

 to an aperture corresponding to the size of the mirror the reflected 

 image is contrasted with that seen directly, and if the definition is un- 

 changed the mirror is marked K. O. with a writing diamond and returned 

 to the maker ; if the object appears distorted its unfitness for use is sim- 

 ilarly notified. A small fee is charged for the examination. 



Royal Observatory, Gape of Good Hope. — In the report for 1882, Dr. 

 Gill states that the observations for the difference of longitude between 

 the observatory anfl Aden are completed. The great comet was observed 

 on every clear night from September 7, and photographs were obtained 

 on six nights. The heliometer measures for the parallax of certain 

 southern stars are nearly concluded. In connection with observations 

 in the northern hemisphere, Victoria and Sappho have been observed 

 for determining the solar parallax by Galle's method. Time of contact 

 at the Transit of Venus was noted by six observers, and heliometer 

 measures were made during the transit. — {Monthly not., March, 1883.) 



The Observatory at Melbourne. — The seventeenth annual report of the 

 board of visitors of this establishment, together with the report of the 

 Government astronomer, Mr. Ellery, for the year ending June 30, 1882, 

 has been received. The meridian work with the transit-circle was for 

 the most part limited to observations of standard stars, for the ordinary 

 purposes of an observatory, and the determination of places of stars 

 used for positions of comets. The 8-incb equatorial had been arranged 

 for the observation of the small planets Victoria and Sappho during 

 the last autumn, according to a programme agreed upon with several 

 European and American and other southern observatories, with the view 

 to another determination of the solar parallax. The large reflector was 

 employed on celestial photography, for sketching a number of Sir John 

 Herschel's smaller nebulae, for drawings of comet 1881, IV, &c. The 

 nebulas about r/ Argus was examined on three evenings, and was found 

 to agree very closely with the drawing made in 1875. The majority 

 of the smaller nebulas were found to accord well with Herschel's de- 

 scriptions. Nos. 57 and 1423, however, were much fainter than Her- 

 schel indicated, and Nos. 1655 aud 2181 differed considerably from his 

 description. Two hundred and seventeen photographs of the Sun we?e 

 taken. A new transit circle has been ordered from Troughton and 

 Simms. — Nature. 



The Sydney Observatory. — An octavo pamphlet of 16 pages has been 

 distributed by the Sydney Observatory which gives the history and 

 progress of astronomy in New South Wales from 1786 to 1883. The 



