POTATO-DIGGER. In their present best forms these machines are of very recent development, superseding the plow type. The design is to raise the roots all to the surface, clean them from adhering dirt, and leave them in a row convenient for basketing, yet with out marring their skins or bruising them.
The Prwyn Putato-digger, Fig. 1, does not turn over the earth, or roll the tubers, but raises them bodily with their earth-bed with a toothed scoop, though lifting as little matter as is consistent with obtaining all the crop. The lifted mass is delivered upon an elevator consisting of a series of transverse rods, carried by endless side-chains up the surface of a grate inclined upward and backward, and having open slots which extend in the di rection of the elevator movement. At the rear, or delivery end of the elevator, is an agitator, or separator, to sift out and drop to the ground any remnants of dirt which may have failed to screen through the elevator grate bars. The elevator speed corresponds to the speed of travel of the machine, so that the crop is lifted high enough to clean it, but otherwise virtually stands still while the digging appa ratus glides beneath it, leav ing it lying on the ground under which it has grown. The agitator is a row of re volving serrated disks. The rear ends of the elevated grate-bars swing freel, and thus avoid wedging and catch ing obstructions, and the agitator disks yield for the same purpose. The dip of the scoop is adjustable to suit various soils. A hand lever adjusts the agitator to suit conditions of work. To avoid heavy shocks, the degree of lift in the pull by the team is automatically controlled by a spring compressed under _ a regulating nut ; thus it is claimed an access of draft lifts the scoop-point momentarily if any earth.fast obstruction is encountered, but allows it to sink again to the depth adjusted for when the obstruction is passed over, making the ma chine available even on somewhat stony and stumpy ground. Only chain gearing is used, placed out side the driving-wheels. No wood is employed in construction—the entire machine is of metal. The
draft is communicated through two large curved side springs, to relieve machine and team from sudden jar, The machine is used not only for digging potatoes, but other root crops and for peanuts.
Howard's English. Fig. 2, has driving-wheels with prominent transverse tractor spuds on the face, and also a flange to run the wheels smoothly on hard roadways. Just over he stem of the shovel a series of forks passes in rotation, adjustable by lever, to deliver right or left. A hand lever in front regulates upward pressure on the shovel, or may be operated to throw all weight on the driving-wheels for transport, or in making turns at row ends. The operator steers the course of the machine by a tail-handle.
Deere's Root-digger, Fig. 3, depends on sifting soil from the unearthed roots between rear ward, upward extending rods, agitated by a knocker-wheel which is rotated by contact with the ground.
The Mover Potato-dig,yer, Fig. 4, is chain geared. It elevates tubers and vines together, discharging the vines on the left, at the rear of the elevator, and the potatoes straight off behind to the ground. At the rear of the elevator is a back rack, having a fore-and-aft motion, to slide the tubers backward from the vines without bruising them. and it may be lowered so as to deliver them with but a slight fall, The depth of digging is regulated with a hand lever by the operator, without halting. Four horses are used. A duty of' six acres or more per day is est boated. Cog gearing is to be avoided in machines of this class, since the cloud of dust produced is peculiarly wearing on such mechanism.
/le Triumph Potato digger, Fig. 5, has no gearing, either cog or chain, hat depends on the upward motion of the two wheels at their rear part. They are armed with a rack of rods to receive the potatoes and trash from right and left mold-boards of the dig ging plough, and separate them by agi tation of the rods. T It e s e rots are fixed oblique to an inner rim on each of the two wheels, in such a manner as to slide the potatoes into a row behind the ma chine. It is claimed to be suitable for two horses.