PLATE i 
The root-pulling machine in operation. The com stalks were first cut off at a con¬ 
venient height. The upright standard next to the scale is open in the center at the 
bottom so that the corn stumps pass through it and the machine need not be lifted 
over them. The scale used was a Chatillon spring balance graduated in tenths of 
pounds with a capacity of 120 pounds at the scale. The maximum pulling resistance 
measured so far was 865 pounds. The scale is hooked to the beam by means of a chain 
so that it can be hooked at any height which will bring the beam into a horizontal 
position when the greatest strain is being exerted. 
