combined focus about one-twentieth of its former value. a 
The pictures of the sun taken with this instrument were better 
than those made by my large telescope, in which no attempt had 
been made to correct the photographic rays. 
Being unable to accompany the expedition, I made a series of 
pictures of the eclipse at home, upon which are seen the nuclei 
and penumbre of the spots, the gradation of light of the sun's — 
disk, and the serrated edge of the moon projected upon the 
sun. They show, however, none of the fogging of the moon's 
surface, commented upon by other observers, nor a greater in- 
this 
In the autumn of 1861 I began to experiment with a eres 
ing telescope with silvered mirror, which recommended Itse 
both by the simplicity and ease of its construction and the er 
was 
ground and approximately figured by Mr. Fitz, and in its peye - 
