row of potatoes, and the row lifted and deposited on the elevator, which gradually shakes out the soil and leaves the potatoes in a row on the ground in the rear. These require two to four horses, according to conditions, and do better work on soils free from stones. The Standard Digger is different.

A divided shovel

FIG. 43-THE REUTHER POTATO DIGGER

lifts the row onto a shaker, which separates the potatoes and soil, leaving the latter on the surface behind. This digger works well when potatoes are ridged or planted shallow, but when deep it does not do so well.' One other form used successfully in Canada and Great Britain consists of a strong frame on two wheels and a small wheel in the front and rear. It carries a set of revolving forks working at right angles to the share,

1 Minn. Bul. 52, p. 439.

which pass underneath the row and raise it. The forks throw the potatoes and soil against a screen, which lets the soil through but deposits the potatoes

in a row.

Several good diggers are made on this plan. Two or three horses are used.

With a mechanical digger, four to six acres can be dug per day, and eight to sixteen hands are required to pick up. The cost of digging should not exceed two cents per bushel, and may be much less. Another advantage of a digger is that if the land is clean it needs harrowing only to be in excellent shape for seeding to wheat.

CHAPTER XIII

STORING

POTATOES may be stored in the open in piles covered with straw and earth, in cellars or root-houses, according to the climatic conditions.

Piles. These are useful for temporary storage in the North. Dig a trench about 3 or 4 inches deep, 3 feet wide, and as long as desired; make the bottom per

FIG. 45-POTATO SHOVEL

fectly level and firm, so that a potato shovel (Fig. 45) may be used on it when moving the potatoes. Throw the soil from the trench onto each side, making a bank about 15 inches wide with it. This will give a trough about 7 inches deep in which to empty the potatoes. Pile the potatoes neatly, so that the face of the pile at the center will be 3 feet or so high. When sufficient potatoes are stored, place about 3 inches thick of rye or wheat straw (oat straw being liable to heat and become mouldy) with the butts down and heads up on the sides and one end of the pile, leaving the other end for additional potatoes (Fig. 46). Then cover the straw

with soil, beginning at the bottom and piling it toward the apex; 2 or 3 inches thick will be sufficient near the top with the straw, and 6 or 7 inches at the base. Finish the surface off by patting it with the spade so

that it will turn rain. Dig a channel all around the pile, using this soil for the covering. The bottom of this channel should be below the floor of the pile, and have an outlet to let off water, thus insuring a dry bot. tom for the pile. Leave the ridge of the pile open to permit the moisture to escape when the potatoes "sweat." If it is desired to hold the potatoes in these

piles over winter, more soil or old hay must be put over them as the frost comes on. The mouth of the pile should be closed at night, and care should be taken to have no potatoes left on the ground at night. Rain or frost may come on and injure them, or retard the work. Sufficient covering must be put on the piles to prevent the rain and sun discoloring the potatoes. I have known a whole crop ruined by inattention to this point. The rain browns them, and the sun makes them green and unsalable. This method is not advisable in the Northern States unless one is sure that they will not want to sell or put up the potatoes until spring, as the pit cannot be opened during frost or in wet weather, and in spring moving potatoes on wet land is objectionable.

Cellars. If seed potatoes only are held, they may be kept in trays, bushel boxes, or barrels, storing these so that air can circulate under and round them, or they may be held in bins.

Construction. The location of the cellar should be dry and well drained. It should be built underground, of concrete, brick, or stone walls, with a plastered ceiling if a building is above it, to make a dead air-space between the plaster and the floor. Concrete walls are readily made with clean gravel, sand, and cement, with boards to hold the material while settling. Use one part of Portland cement, three of sand, and six of gravel; mix the sand and cement, then add the gravel; wet and mix, and fill into the wall-space. To hold it in position while drying it is customary to use 1-inch boards, nailed onto 2 x 4-inch studding, which may be placed 1 foot 6 inches on centers. To pre