690 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Projecting from e at right angles is the metal-piece k i on which, in 
a groove, not visible in the figure, moves the slide D. This movement 
is effected by the screw B which is attached to i at k and k! and works 
in the nut g' fixed to D. The amount of displacement, as before, is read 
off on the millimeter division on D by means of the index i'. 
Fig. 97. 
The object-holder 0 is firmly clamped against the inner edge of the 
slide D by the arrangement r r' e on the one side, and m E p on the 
other. At r is a cross-piece sliding on D, and this is moved forward to 
a position corresponding to the size of the object-holder, where it is 
clamped by the screw e ; the left small side of the object-holder is then 
pressed against the projecting-piece r. In rigid connection with the 
slide on the right is the piece m, and sliding in this is the angle-arm E, 
which can be clamped by the screw e'. In E slides the metal-piece n 
which carries at one end the movable square piece p, while it is pressed 
at the other by the steel spring o. Thus by loosening the screw e', 
pressing E up against the object-holder and then again clamping e\ the 
object-holder is firmly fixed in the apparatus, so that its displacement 
can then only be effected by means of the screws A and B. 
The right small side of the object-holder is free, so that any strain 
upon it is prevented. 
The apparatus can be easily fitted to any rectangular stage the side 
of which exceeds 80 mm. in length. 
The method of using the apparatus as a “ finder ” needs no explana- 
tion, except that it must be fixed to the stage-plate in such a way that 
the projecting piece seen at S shall be flush with the front edge, and 
that the plate r r' must be moved back as far as it will go to the left 
before the object-holder is clamped in. 
