New Reflecting Telescope and Observatory. 21$ 



themselves to the curve without strain. The whole runs on 

 flat rails which are attached to the main ribs of the opening, 

 and run down as flying rails on the opposite side of the 

 dome, so that, as the shutter is drawn up by the ropes 

 attached to it inside, it simply slides over the top. As the 

 opening extends more than to the top centre of the dome 

 so as to give ready access to the zenith, the lower portion 

 of the shutter is arranged to open outwards on hinges. 

 This is done to shorten the length of the main shutter and 

 prevent its dipping below the skirt of the dome when 

 opened to the fullest extent. The canvas is the strongest 

 sailcloth, of which 160 yards were required ; it is rendered 

 waterproof with several coatings of boiled oil, over which it 

 has been painted a silver grey. 



The dimensions of the observatory are 20ft. diameter 

 internally, 22ft. externally, and 14ft. 6in. from the floor to the 

 highest portion -of the dome. A transit house on the west 

 side, 8ft. by 4ft, contains a transit telescope by Dollond, 

 2^in. aperture, 30m. focal length, and completes the equip- 

 ment. 



Although primarily intended for general observational 

 rather than micrometrical work, I propose, first, by watchful 

 attention of the lunar surface during successive lunations, 

 especially of such spots or craters as have already been 

 suspected as showing signs of recent change, to aid in some 

 small degree in obtaining the required information which 

 will satisfactorily decide this important question. The 

 planets will also receive a considerable amount of careful 

 scrutiny, and such other objects as may from time to time 

 claim special attention. This telescope, being particularly 

 suited, owing to its perfect achromatism, for photographic 

 purposes, a new branch of astronomical research which is 

 capable of much greater development, I hope to devote 

 some time and effort in this direction, and trust I may be 

 able now and again to bring before you results which may 

 be of interest and service in the general advancement of 

 astronomical enquiry. 



