106 
8UMMARY OF CURRENT RESEARCHES RELATING TO 
long spiral spring ; F engages a tooth of the upper disc. If now the 
lever A is moved to the right, F will continue to engage the tooth of 
the disc until the guide-post L comes in contact with the inclined plane 
on the margin of C, when the pawl F will be disengaged from the tooth 
of the disc exactly at the zero point of the scale. It will thus be seen 
that, no matter how far A may be moved, F will act only through a 
certain definite distance, governed by the position of the inclined plane 
of C, and that the amount of elevation of the object at each cut is 
definitely indicated by the position of the pointer H on the scale. 
Some Improvements in the Reinhold-Giltay Microtome.* — A de- 
scription of this instrument has already appeared in the Society’s 
Journal,! and Dr. J. W. Moll now describes some improvements. 
Fig. 22. 
(1) The wooden table bearing the instrument is now replaced by 
one of cast iron, designed by Messrs. Gips, instructors at the Delft 
Polytechnic (fig. 21). 
(2) The reading-off apparatus. — Fig. 22 shows the old form of the in- 
strument, and will facilitate comprehension of the changes. By loosening 
the screw, the segment x can be adjusted so that at each stroke of the 
wheel K, 1 to 40 teeth can be rotated. The number of mikrons corre- 
sponding to the teeth is given by the indicator on the segment. The 
divisions of the segment are marked on its upper nickelled surface, and 
* Zeitschr. f. wiss. Mikr., xv. (1898) pp. 23-9 (4 figs.), 
t Cf. this Journal, 1893, pp. 700-11. 
