188 Miscellanies. 



liant, and the field of view much greater) was remarked with the use 

 of Mr. Holcomb's highest magnifier, giving a power of two hundred 

 and fifty. 



As an illustration of their comparative performances, it was re- 

 marked that the waved appearance of the outer declivities of the 

 craters of some of the apparently extinct lunar volcanoes, indicating 

 the successive depositions of the lava, was more manifest with a pow- 

 er of 400 in the reflector. 



The immersions of 3 and 4 Geminorum, of the sixth and seventh 

 magnitude, were observed at the same instant of time in each. 



The same occurred the evening before with a star of the eighth or 

 ninth magnitude. The immersions, however of two very small stars, 

 apparently of the tenth or eleventh magnitude, were observed with 

 difficulty in the refractor, but could not be observed at all in the re- 

 flector. 



The companion of Polaris was best seen when the moon was up, 

 in the refractor, but in the absence of the moon was readily seen in 

 both. 



Castor was easily divided with the lower powers of either, but in 

 the case of this as well as other binary, or double stars, the dark 

 space between the stars was less disturbed by scattering rays in the 

 reflector than in the refractor. 



£ Bootis was seen double in each, but more distinctly in the re- 

 flector, fjt, Draconis, 7 Leonis, and 4th and 5lh s Lyrae were seen 

 distinctly double in both instruments ; |x Draconis from the equality 

 of the disks and softness of light presented the finest appearance. 



7 Virginis, with a power of 350 in either telescope gave, no certain 

 indication of being double : some of the members of the committee 

 were of opinion, that it was slightly elongated. It was stated by the 

 artist that his reflector would divide stars distant 3" from each other. 



Estimating the distance of the stars observed by the late observa- 

 tions of South, Struve, and Herschel, Junr., the committee were 

 of opinion that his instrument is adequate to the distinct division of 

 double stars distant from each other 2.5''. 



The motion of this instrument plainly mounted was steady, and 

 with the finder, even without rack work, objects were easily made to 

 range with the centre or line of collimation of the instrument. 



The position of the observers with the Herschelian telescope was 

 natural and easy in contemplating objects liaving 70^ or 80° of al- 



