24 



CHAP. III. THE BALANCED CRESCOGRAPH 



decrease or increase in the rate of the compensating fall 

 (fig. 9). Growth thus becomes accurately balanced, so that 

 the tip of the plant remains exactly at the same level. 



I take a concrete example in explanation of the adjust- 

 ment for compensation. Different plants exhibit consider- 

 able difference in the rate of their growth ; in a large number 



£ e 



Fig. 9. Diagram of Method of Falling Weight. 



Compensation of growth-movement effected by equal sub- 

 sidence of the holder supporting the plant (p). Adjusting 

 screw (s) regulates the speed of the governor (g), and the 

 rate of subsidence of the plant, w, heavy weight actuating 

 clockwork. 



of cases the rate varies from • 17 [i to i -o jx per second, the 

 range being about six times. The construction of this par- 

 ticular apparatus enables the balance to be secured within 

 these limits. The adjusting mechanism consists of a centri- 

 fugal governor and a frictional resistance. The two arms of 

 the governor can be increasingly outspread by a right-handed 

 turn of the screw S {see fig. 9). This increases not only the 



