Patent for improvements in cotton-choppers by using a crown-wheel attached to one of the ground-wheels of the chopper. When the ground wheels impart motion to the crown wheel, which in turn communicates motion to the pinions of the shaft. This shaft drives the two sprocket-wheels; the sprocket wheel that located in the rear portions of the crank-shaft imparts motion to the crank-shaft, which drives the vertical choppers. Illustration is included.