! 



264 HISTORY OF ASTRONOMY. 



A large telescope, manufactured by Mr. Alvan Clark, 

 of Cambridge, Massachusetts, has recently been received, 

 and mounted under the dome. The aperture of this 

 telescope is seven and a quarter inches, and its focal 

 length eight and a half feet. A block of stone, weighing 

 about 1800 pounds, standing on the top of the brick 

 pier, supports the instrument. The top of the stone is 

 level, and a frame of cast-iron, clamped to the stone, 

 sustains the polar axis. The clock, which gives the 

 equatorial movement, is let into the top of the stone, 

 and is regulated by a pendulum, while the motion is 

 rendered continuous and nearly uniform by means of an 

 elegant contrivance of Professor W. C. Bond, called the 

 spring governor. With this telescope Mr. Clark dis- 

 covered two new double stars, in one of which the dis- 

 tance of the components is but three-tenths of a second. 

 This instrument cost $1,800, and was presented to Am- 

 herst College by Hon. Rufus Bulloch, of Eoyalston. 



CHARLESTON OBSERVATORY, SOUTH CAROLINA. 



This observatory was built by Professor Lewis K. 

 in his own garden in Charleston. It is a wooden 

 building of 10 by 15 feet, with a sliding roof. It con- 

 tains a five feet transit instrument, by Troughton, solidly 

 mounted on a pier of red sandstone, and commands the 

 meridian to within ten degrees of the horizon on either 

 side. There is also a five feet telescope, by Adams, of 

 London, mounted equatorially, and provided with a po- 

 sition micrometer, by Troughton and Simms, and two 



