466 Astronomical Society. 



such stars as might be situated near Mars at the time of his 

 opposition, were made at tlie public observatories : whereby 

 the true position of the planet in the heavens would be more 

 correctly ascertained. 



The follovi'ing are the mean positions of the stars above al- 

 luded to on the 1st of January 1826. 



The reading of the description of the large reflecting 

 telescope and frame made by Mr. John Ramage, of Aber- 

 deen, was terminated. Mr. Ramage has, ever since the 

 year 1806, devoted much of his time to the construction of 

 reflecting telescopes of large sii^e, and of convenient frames 

 and supports, in which firmness of structure and flicility of 

 adjustment to any required position, should be equally at- 

 tained. The telescope now described has a twenty-five feet 

 tube. The platform upon which the telescope is placed, and 

 revolves at pleasure, is a strong circular rail-way of cast iron, 

 twenty-seven feet and a half in diameter, and tour inches in 

 breadth. The horizontal azimuthal motion is upon concen- 

 tric rollers, round a central pivot. The stand or frame, though 

 simple in its construction, cannot be vei-y intelligibly described 

 without a model or a diagram. The tube of the telescope is 

 elevated to the required altitude by a winch and tackle of 

 pulleys. The gallery in which the observer stands is adapted 

 to the proper height by a similar winch and tackle ; and to 

 prevent accident from the breaking of the ropes, it is sup- 

 ported at each side by two moveable bars that fall into the 

 steps of the ladders, which constitute a part of the frame. The 

 lower end of the tube rests upon two rollers, and at great al- 

 titudes moves forwards, so that the tube itself is capable of 

 adjustment to all positions, from that which is nearly horizon- 

 tal to that which is nearly vertical. Without quitting the 

 gallery, the observer can move the tube both horizontally and 

 vertically upwards of 10°, and can with the utmost readiness 

 (independently of an assistant) direct the telescope to any point 

 in the heavens. All the motions ai"e efl'ected by means of a 



verv 



