Growth. 19 



itself to the pull of the lever, and the exact point that may be 

 read on the ruler scale above the lever should be noted. Now 

 make readings at intervals of two or three hours during the 

 day and as late at night as possible. Begin readings at similar 



Fig- 9. Pulley auxanometer. The cord /is passed over a small wooden pulley, 

 and a small weight is attached to its end at G. The wooden lever Z is attached 

 to the free face of the pulley, and counterweighted at g in such manner that, when 

 the instrument is not attached to a plant, the tip of the lever rises. The end of the 

 lever moves over a paper scale suitably supported. After Oels. 



intervals on the following day (Fig. 8). At what hour of the 

 day is growth most rapid ? What is the total amount of growth 

 during the day ? 



The same purpose may be accomplished by an auxanometer 





