C 63 ] 

 VIII. Proceedings of Learned Societies. 



ROYAL ASTRONOMICAL SOCIETY. 



[Continued from vol. xxxiii. p. 480.] 



June 9,"V[ OTICE of the principal English Observatories. Ex- 

 1848. -^^ tracted from official or direct sources. 



Two British observatories only are, properly speaking, public, — 

 those of Greenwich and Edinburgh. The Observatory of Oxford 

 was built and is supported by a bequest under Dr. RadclifFe's will : 

 it is under the control of private trustees. The Cambridge Obser- 

 vatory was erected principally by private subscription, and is sup- 

 ported in part by the funds of a professorship founded by Dr. Plume, 

 but mainly out of the University chest. The RadclifFe observer 

 makes an annual report to his trustees ; and Visitors appointed by 

 the Cambridge Senate draw up yearly a statement to be laid before 

 that body. Since the appointment of Mr. Airy to the Royal Obser- 

 vatory, a minute report of all proceedings and changes in that esta- 

 blishment is read to the Board of Visitors at the Annual Visitation in 

 June. 



Greenwich. 



It has been mentioned in former numbers that the meridional in- 

 struments at Greenwich are deficient in optical power, and that the 

 Astronomer Royal proposed to replace the mural circle and transit 

 by a single instrument, viz. a transit circle, which is to be erected 

 on the site of the present circle-room. In his report to the Visitors, 

 Mr. Airy says, — 



" An object-glass of eight inches clear aperture and eleven feet six 

 inches focal length having been placed in my hands by Mr. Simms, 

 I carefully examined it. I found that it showed some objects not of 

 the closest class (as e Bootis and ^ Cancri) better, I think, than I 

 had seen them before ; that it separated ij Corona; ; that it did not 

 separate y Coronae (which, having witnessed the difficulty of that 

 star in the great Pulkowa refractor, I was prejDared to expect) ; and 

 that it dispersed light no more than the best Object-glasses usually 

 do. At my recommendation, therefore, this object-glass was pur- 

 chased by the Lords Commissioners of the Admiralty, at the price of 

 275/. I have now to explain the form in which I propose to mount 

 it. No verbal description, probably, can dispense with reference to 

 the model*, and I will therefore confine myself to the leading points. 

 I propose to mount it as a transit circle, its Ys bearing solidly on 

 the piers far from their edges, and having no adjustments ; the axis 

 carrying two nearly similar circles on the east and west arms, one 

 for clamping, the other for the divisions. I propose that the clamps 



* A small model of the proposed transit circle was exhibited at the Visi- 

 tation in June ; and the Astronomer Royal, having obtained the consent 

 of the government, is proceeding with the construction of the instrument. 

 A full-sized model has been made and approved. The circle-room ia 

 rebuilding. 



