96 = -E. Cutter—Microphotography with Tolles’s Objective. 
rod, and another screw with a milled head goes through the 
other eye into other end of the rod. The rod is thus secured 
and rotates by turning the milled head; 17 inches of the rod 
are covered with sand set like sand paper; in the cut this is 
covered by a sleeve of enameled cloth as the sand is detached 
by contact. When used the sleeve is pushed back and a braid or 
tape is run over the rod and around the milled head of the fine 
adjustment. A pin secures the ends of the tape when the 
proper tension is made by drawing them over each other. The 
delicate focussing is made by the hand of the operator while 
the eyes are on the ground glass plate of the camera; the tape 
is not shown in the cut. 
Remarks.—It will be noted that the peculiar features of 
this arrangement which differ from Col. Woodward's plain are, 
besides the portability ; 1, The size of the condenser; 2, The 
absence of the ammonio-sulphate copper or alum cell. 
as if this cell was a disturbing element still, though in the 
hands of the father of modern microphotography. s 
e have taken a large number of negatives, some of which 
have received honorable mention abroad: see Journal de 
Micrographie, Paris, October, 1877, and have used no device to 
cut off heat; hence we feel justified in saving ourselves the 
trouble of a, to us, unnecessary appliance. In our opinion this 
cell has stood in the way of the more general adoption of the 
reproduction of microscopic objects by photography. W 
think it is a good rule to use the simplest and fewest things to 
accomplish a purpose. ee 
For what precedes it is seen how the ,'; inch objective was 
used for photography. The object, for instance, enlarged white 
blood corpuscles, was displayed on a slide by the sudden dry- 
ing of a thin film of blood. The corpuscles were found b 
means of a low power and centered in the middle of the fiel 
