258 



LIFE MOVEMENTS IN PLANTS 



rate of subsidence ; this became magnified by the Cres- 

 cograph and appeared as a series of oscillations about a 

 mean position of equilibrium. This particular defect was 

 obviated by the substitntion of a fan governor for the 

 balance wheel. But the speed of rotation slows down with 

 the unwinding of the main spring, and the balance obtained 



Fig. 94. — Photographic repvoduction of the Balanced Crescograpb. L, L^, magni- 

 fying compound lever. R, recording plate. P. plant. C, clockwork for oscillation of 

 the plate and lateral movement. G. governor. M, circular growth-scale. V, plant- 

 chamber. 



at the beginning was found to be insufRcient later on. 

 The difficulty was finally overcome by the use of a heavy 



