ASTRONOMICAL OBSERVATORIES. 207 



feet, and such an instrument as he was pleased to send as 

 a specimen of his powers." This instrument has a focal / 

 length of 10 feet, and an aperture of 5 inches. The ob- / 

 ject-glass is almost perfectly achromatic. For objects 

 that require a fine light, as the nebulae and smaller stars, 

 this instrument exhibits great superiority, and its defin- 

 ing power is equally good. It has a variety of eye- 

 glasses, and a spider-line micrometer of the best con- 

 struction. 



The style of mounting of this telescope is not equal to 

 its optical character. It has an altitude and azimuth move- 

 ment without graduated circles, and is rolled about the 

 room upon casters. The location of the instrument was 

 peculiarly unfortunate. It was placed in the steeple of 

 one of the college buildings, where the only view afforded 

 of the heavens was through low windows which effect- 

 ually concealed every object as soon as it attained an alti- 

 tude of thirty degrees above the horizon. Under these 

 circumstances, the telescope has proved less serviceable 

 to science than might otherwise have been anticipated. 

 On one occasion, however, circumstances gave this tele- 

 scope considerable celebrity. The return of Halley's^ 

 comet, in 1835, was anticipated with great interest. The 

 most eminent astronomers of Europe had carefully com- ) 

 puted the time of its appearance, and the results of their 

 computations had been spread before the public in all the 

 popular journals. All classes of the community were 

 impatiently watching to learn the result of these predic- 

 tions. The comet was first observed in this country by 



