E. Emerson on Improvements in the Photographic Camera. 229 
This instrument I had intended to use upon the focussing 
i- 1. 
light caused by the opa- ground glass, having fine lines drawn by the 
diamond on the surface farthest from the micro- 
—O, Achromatic objective—-E, Eye-piece. 
2 
character, mi ght be en- and out.—ET, Exterior og er a projection 
tirel trig] at the objective end at right angles, so as to ap- 
y overcome. Atrial ly it secarntely ro the flat surface of the glass, 
of the microscope formed a telescope of considerable power, the 
lenses reciprocally supplementing each other, so that no matter 
diced by the lenses of the camera might be 
nearest to the lenses of the camera; the microscope 
carefully adjusted to distinct vision of these li 
difference between the chemical and vi 
Tangement afforded a means of adjusting with the greatest ac- 
curac 
By thi ‘nag very small objects, such as a sin- 
gle Jeaf or a : pone aig é peek distant, were distinctly 
in distance was made apparent; d tl 
Power of the single microscope. The use of a very small dia- 
pragta enabled me now to ey : ce 
Objects visible in an extended lanascape, 1 
ar examination under the compound gicrosiope Wir a ences 
of 150 to 200 diameters; or, in other words, wit tet ny 
igh as the structure of the collodion would bear. Up t 
