ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
531 
the pins x acted as clamps. The curved bars under the lower plate 
were for a glass tube of liquid, and in this case the springs clamped the 
two lowest plates. Two reversible tablets (Y, a), white one side, black 
the other, were provided for opaque objects. The reversibility was 
attained in Y (a small round ivory tablet) by suspending it on two small 
pivots in a brass bracket at the end of the crooked arm z. With the 
large tablet a, reversibility was attained by a single pivot, and the arm 
b was crooked so as to make a always horizontal. 0 is a pair of forceps 
also intended for opaque objects. The micrometer y is a Parisian inch 
divided into a decimal scale, and was intended for estimating the magni- 
Fig. 127. 
fying power. The whole apparatus was fitted on the lid of a box, which 
contained drawers for the reception of the various parts when not in use. 
Fig. 127 shows the “ anatomical ” arrangements, after the manner of 
Lieberkiihn’s “ Anatomical Magnifying Machine” (1745). At the back 
of a board a frog’s web or other such object was spread out, and the lens 
of the Microscope arranged so as to explore all the parts opposite the 
perforation. 
Fig. 128 shows how an extension of “ universality ” in the form of a 
tube Microscope could be arranged for those who preferred such an 
instrument. The tube was screwed into the ring b , and a second ring 
working radially from a centre-joint d received the lens. This second 
ring could be swung aside and the lens changed when desired ; the 
