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IOWA ACADEMY OF SCIENCE Vor.. XXVIII, 1921 
PLATE IV. 
Explanation of Apparatus. 
1. Wire bringing current from storage batteries. 
2. Wire of primary circuit to signal magnet at M. 
3. Wire of secondary circuit to muscle in glass chamber C. 
4. Wire extending from chronometer to time marker magnet M. 
B. Lever arm marking base line. 
C. Glass chamber containing muscle. 
D. Stop cock, controlling liquid in glass chamber C. 
H. Kimograph stand equipped with a modified Zimmerman contact 
breaker. 
K. Kimograph. 
I. Inductorium. 
L. Writing lever to which muscle is attached. 
M. Double Deprez signal magnet used for time and signal markers. 
R. Rheocord. 
T. Thermometer. 
