304. LL. M. Rutherfurd on Astronomical Photography. 
Art. XXXVII.—Astronomical Photograyhy ; by Lewis M. 
UTHERFURD. . 
My present observatory is a circular brick building of twenty 
feet internal diameter, with a light revolving roof supported on 
twelve wheels which are fixed to the stone coping of the walls. 
e opening, two feet wide, extends from side to side with 
simple shutters, which, when elevated on the weather side, serve 
to prevent the wind from blowing into the observatory and 
shaking the telescope. Opening from the west side of the 
Equatorial dome is a small transit apartment with computing 
room attached. This observatory is in the garden of the house 
where I reside. The transit is 189 feet N.W. from the Second 
Avenue, and 763 feet N.E. from Eleventh street. It was 
erected in the summer and autumn of the year 1856, The equa- 
torial, by Fitz, is a very substantial instrument, having circles 
divided on silver 18 and 20 inches in diameter. 
The objective is of 114 inches aperture, and fourteen feet focal 
length, and was corrected for figure by myself after the methods 
and directions of Mr. Fitz. It is a fine glass, capable of show- 
ing any object which should be seen by a well corrected objec 
tive of those dimensions. 
The observatory is low and therefore cannot reach any object 
near the horizon, but I prefer losing such observations to the 
tremors and expense of a high structure. : © 
The transit room has been used on several occasions by the 
U. S. Coast Survey in their telegraphic operations for longitude. 
It is 04, 12, 15-475 E. of Washington, and in latitude 40’, 43, 
48538; the latitude being the result of observations with ¢ ee 
zenith telescope upon twenty-four pairs of stars by the observ: 
ers of the Coast Survey. a 
During the winter of 1857-58, Messrs. Alvan Clark +O 
constructed, and in the spring attached to the equatorial, a pi 
ing clock of the highest merit. It has a remontoir escapemens 
similar to that of Bond’s spring governor. : viet 
Having seen with great interest the photographic experi”! id 
conducted at the observatory of Harvard College, 
as soon as the clock should be in working order, 
a ee 
ret eee 
ER Re ate eee Rt nee 
ive was about ,7; of an inch outside the visual focus. per 
done b 
view ots 
