Vion, Xl. NO. 7 — BOTANICAL GAZETTE JULY, 1667. 
A simple and inexpensive self-registering auxanometer. 
HERMON C. BUMPUS. 
° 
(WITH PLATE VIL.) 
aed be 
glass which has been held over a burning rag previously sat- 
urated with turpentine. The smoked plate, d, is held by a 
and as a result we shall have a zigzag line, the distance be- 
tween every two angles of which signifies a regular interval. 
