1892. | A Simple Self-registering Auxanometer. 107 
fact, the relative growth curve produced by a large tension is 
correct, provided the first hourly registrations be neglected. 
. The registering apparatus consists of a cheap nickel clock 
costing seventy five cents. The minute hand is removed 
from its spindle and a piece of thin metal carrying the cylin- 
der is put on instead; one end of this piece of metal is 
pointed and of sufficient length to answer as a substitute for 
the minute hand; the other end supports the cylinder and is’ 
bent outwardly, for the purpose of having the latter stand out 
some distance from the dial. At its point of attachment to 
For its successful revolution it is important that all the parts 
should be exceedingly light. The clock used by us was not 
in the least affected by the weight of the cylinder, and was 
Capable of running 30 hours without re-winding. If, however, 
th 
sli 
In 
axis of rotation; by careful compensation a weight of con- 
be made to revolve successfully. 
Pe disk of metal be constructed so as to slip over the hour 
eons A cylinder of metal, wood, or even a glass-jar, 
smoked glazed paper, or millimeter-ruled paper, 
Placed upon the disk to record the growth. With 
ni tuled Paper it is necessary, of course, to substitute 
"NK pen for the metal one. 
