base-boar d (B), which can slide forward or backward between 
guides on the table (T). The coarse adjustment is effected, first 
of all, through this sliding movement of the base, and then by 
a Screw-movement of the object-carrier (C). The fine adjustment 
is made by turning the objective, which works in a fine screw. 
Extraneous light is excluded by inclosing the whole apparatus 
_ Ma tin box (Gh) provided with a wide side-door. 
__ The size and distance of the picture vary within relatively 
large dimensions, so that an ordinary photographic camera could 
hot conveniently be employed. The arrangement is such that 
_ ile picture is projected upon the wall of the dark-room, in front 
of the objective, instead of a ground-glass behind it, as in the 
ordinary camera. 
of ` The dark-room is divided by a partition (P), which is provided 
With a door and a sliding screen (S). On the wall opposite the 
n is fixed a large frame (F), which carries a glass plate (PI). 
pa Mage is first brought to a focus on a sheet of white paper 
behind the glass plate; and then, after closing the screen, the 
white paper is replaced by the photographic paper. 
de- photographic paper, known as the “ Eastman bromide- 
The rack bearing all these parts has two feet resting on a 
eo aE ne ANA 
ae AA A IE E T a paren a a Pb E g e a 
ver paper,” is sensitive enough for use with lamp-light, and 
oe manipulations are extremely simple. ao 
SA S time of exposure varies according to the magnification 
ee diaphragm employed. With the Steinheil aplanatic and 
ee. (4) an amplification of ten diameters requires an €x- 
