PHOTOMICROGRAPHY. 115 
of Dr. Woodward’s work in the libraries of the Royal Microscopical 
Society at King’s College, and of the Microscopical Society of 
Liverpool. 
Apparatus.—The apparatus employed need not necessarily be 
expensive. Any small microscope, with fine and coarse adjustments 
for focussing, and an ordinary quarter-plate camera arranged on a 
short base board, will serve for a beginner, and even the camera 
and microscope stand may be dispensed with by the use of a dark 
box, as described in the English Mechanic for February 2nd, 1883. 
It is preferable, however, to have a base-board four feet long and 
eight inches wide, provided with a ledge of wood half-an-inch 
square on each side, between which a block or carriage may slide, 
and upon which a bellows camera can be fixed at such an altitude 
that the flange for.the lens will admit the eye-piece end of the 
microscope, which must be placed in the horizontal position. To 
allow of a wide field it will be well to have the body or tube cut 
off about an inch from the nose, and a screw collar arranged to 
allow of replacement of the tube when it is desired to use the in- 
strument in the ordinary way, or to photograph with the addition 
of the eye-piece. A short cardboard tube fitting in to the lens 
flange of the camera will allow of a taper velvet collar two or three 
inches long being glued thereto, which will serve to keep out the 
light and yet allow free movement of the object-glass for focussing. 
The bellows should possess the greatest latitude of expansion, 
allowing a variation of length of focus from ten inches to thirty-six 
inches. ‘The interior of the microscope body should be lined with 
black velvet to prevent flare on the plate from reflection. When 
the camera is extended to the full limit, a piece of looking-glass 
held in the left hand at a suitable angle opposite the ground glass 
screen will enable the operator with his right hand to focus roughly 
with the coarse adjustment screw. For accurate focussing a rod 
passes under the camera, having at one end a knob as a handle, 
and at the other extremity a pulley one inch in diameter provided 
with a V groove, in which runs an endless cord working the button 
of the fine adjustment, also grooved. The rod and pulley should 
work smoothly to avoid uneven strain on the arm carrying the 
objective, and the fine adjustment should run sweetly and answer 
immediately to the least turn of the rod. A mechanical stage with 
rectilinear motions for carrying the object to be photographed is 
very convenient, but not essential. The stage plate should, how- 
ever, be furnished with levelling screws at the corners for bringing 
all parts of the picture into a flat plane. Both of these appliances 
are to be seen on the instrument before you. 
On the shaft of the fine adjustment screw a short split brass tube 
half-an-inch long is made to slide stiffly, to which a stout wire 
pointer three or four inches long is soldered. A semicircle of 
