a 
244 Coast Survey of the United States. 
pelled to borrow a transit instrument from the State of Massachu- 
setts, an altitude and azimuth circle from Columbia College, 
(now returned,) a repeating circle from West Point, and to pur- 
chase from Mr. Blunt, a Gambey theodolite, imported for his own 
use, which fully justified the high character of the maker. For — 
this department there should be a separate appropriation, and it is 
td be hoped, that next winter the earnest appeals of the superin- 
tendent, supported by some intelligent members of Congress, who 
can appreciate the vital necessity of the case, will be heard with 
favor. In the mean time he is doing all in his power to reme- 
dy the gross deficiencies. A transit telescope has been ordered 
from Simms, and from Gambey a theodolite of the largest class, 
suited to astronomical observations and to the measurement of 
horizontal angles. Encouragement is given to our mechanics at 
home, from whom the smaller instruments are ordered, as they 
are wanted. A theodolite, by Patten, has lately been divided at 
the office with the dividing engine belonging to the coast sur- 
vey. A vast deal of work, such as repairs, new mountings, é&c., 
is done upon instruments in the workshops of the office at Wash- 
ington. The vertical circle of the three feet theodolite has been 
separately mounted during the past winter, and a new horizontal 
circle graduated for the purpose. ‘The fitting of the microscopes 
for the large theodolite has also been altered, so as to render the 
adjustments more easy and permanent. ‘To these repairs may be 
added the making of drawing instruments, and engravers’ tools. 
This work, done under the eye of those who are to use the in- 
struments, is attended with a saving of time and expense. 
The dividing engine of Mr. Troughton, belonging to the coast 
survey, which has been referred to, has been made automatic 
by the mechanical genius of Mr. Saxton. This instrument 
had been but little used. T’'wo days were required to divide 
a circle, and the change of circumstances in the interval, the 
inconvenient position of the workman, and the effect of the 
heat of his body, created doubts of its accuracy after trials by ex- 
perienced workmen. Now that it is self-acting, it performs, in 
one hour and ten minutes, the work which before consumed 
two days. The turning of a crank gives the necessary slow 
motion to the circle, raises the cutter, pushes it forward, and 
draws it back in such a manner, that it marks lines of four dif- 
ferent lengths—10’, 30’, 1°, and 10°, and finally it throws itself 
