530 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
strument in its different forms so clearly that but little description is 
needed. Fig. 125 contains the compass, or skeleton of the apparatus, 
and the accessories, which will be recognised, in their various combina- 
tions, in the other figures. The parts, when fitted together and set upon 
the box-lid as a stand, made instruments suitable for viewing (1) trans- 
parent or liquid objects (fig. 126, upper), (2) opaque objects (fig. 126, 
lower), (3) anatomical objects (fig. 127). The Microscope was simple, and 
the only lens used was set in a circular frame d, inserted into a ring c. 
If the object was transparent or liquid (fig. 126, upper) this arrangement 
with the help of an adjustable glass mirror e, was sufficient ; but in the 
Fig. 126. 
case of an opaque object, a perforated concave silver mirror h, g was screwed 
on to the under side of d , and the light, first reflected from the mirror 
e, was then again reflected on the object (fig. 126, lower). The screw- 
thread g for securing h to d was long enough for adjusting the focus of 
the concave mirror. Thus the opaque object was not only illuminated 
on both sides, but received a maximum of light from above. The con- 
cave mirror is shown in section at h , and in perspective at/; g g is the 
screw-hole for fixing lens-cap and mirror on to the compass leg. The 
little stage for holding the slides R was made of three plates, between 
the upper two of which the slides were placed, and the spiral springs on 
