more likely to result from using this chute than from using the slant or the chain chute.

For dipping pregnant ewes some persons build a movable platform which can be lowered into the vat and raised at will.

FIG. 51.-Ground plan of yards and vat. (Copied from Armatage, 1895, The Sheep Doctor.)

THE DIPPING VAT.

The dipping vat may be made on several different plans: The single oblong straight vat; the double or triple, with turns at the ends; the square; or the circular. In case of single oblong vats, time

4 Gate

FIG. 52.-Ground plan of yards and vat. (Copied from Powers' The American Merino, 1887, p. 304.)

will be saved in dipping if a long vat is used, so that the animals may swim directly through without stopping, and then leave the tank. Very naturally, the longer the vat the more building material and ooze will be required. Vats are in use varying from 10 to 120 feet long.

FIG. 54.-View of the dipping plant at the Union Stock Yards, Chicago, Ill. (This dipping plant, including vat, boiler, etc., cost about $2,500.)

The single oblong vat.-Single oblong dipping vats are shown in figs. 36, 37, 38, 39, 41. These tanks should be made about 2 feet broad at the top, 9 inches broad at the bottom, and 4 to 5 feet deep. The length may be 20 to 120 feet, as desired. One end (the entrance) should be straight, as shown in figs. 42 and 44, or with a steep slant, as shown in figs. 39, 41, and 43, while the last 5 to 14 feet at the other end (exit) should have a gradual slant with cross cleats.

The square vat.-A square vat is shown in fig. 40. This tub should be 5 feet deep and large enough to hold 10 or 12 sheep at a time. The square vat does not present any particular advantages over narrow oblong vats, except that it gives the sheep an opportunity to swim around. This kind of a vat is not in very general use among large herders.

The triple vat.-In the triple vat (fig. 46) the sheep come through the run, or drive, and slide into the first vat at A; swimming in the direction of the arrows, they round the turns B and C, ascend the incline D, and enter the draining pens. The theory upon which this triple vat is used is that upon rounding the point B the sheep bend toward the left, thus crumpling the scabs on the left side and opening the wool on the right; upon rounding the point C they bend toward the right, crumpling the scabs of that side and opening the wool on the left. This is evidently a more theoretical than practical consideration.

Each run should be about 15 to 30 feet long and 2 feet broad; the tank should be 44 to 5 feet deep and 4 to 74 feet wide at the bottom. At the point A, where the sheep fall into the swim, it is best to have the floor of the first run 2 feet wide for a distance of 6 feet, in order to prevent accidents, but beyond that distance the floor may be narrowed in order to save the dipping fluid. If the partitions E and F are not made solid the ooze will circulate more easily and thus remain at a more even temperature; the boards should be close enough together, however, to prevent the sheep from catching their feet in the cracks. A gate should be arranged at D, so that the animals may be delayed in the ooze, if desired. (See also fig. 53 of the triple vat in use at the Chicago Stock Yards.)

The circular vat.-Some parties prefer a circular vat (fig. 47). The advantages set forth in favor of this are, first, a fewer number of men are required to attend to the animals in the tub; second, where it is desired to give any particular sheep an extra long swim, this may be done by quickly closing the gate D at the exit, thus compelling the animal to swim around again, without delaying the other sheep; third, by building a circular vat with a circumference of 30 feet the animals may be made to swim around two, three, or four times, thus gaining the advantage of a tank 60, 90, or 120 feet long, yet with a much smaller amount of building and dipping material.

7204-10

The vat should be 24 feet broad at the top, 9 inches broad at the bottom, and 5 feet deep. To determine the circumference multiply the diameter by 3.1416.

Despite the advantages of the circular tank in saving material and obtaining the advantages of a long swim, there are two rather serious objections to it: First, in the vat shown in fig. 47 it is necessary to throw the animals in by hand, since a chute directed into the circle would lead to accident; second, the circular vat is much more difficult of construction than the straight vat.

These objections may, however, be overcome in several ways, still preserving all the advantages. If a circular vat is preferred and a chute is desired, the object may be attained by building a short, straight vat on a tangent to the circle, as shown in fig. 48. In this case two swinging or sliding gates, A and B, will be required.

The double vat.-All of the advantages of the circular vat may be combined with the easy construction of the straight vat by building a straight tub with a double channel, as shown in figs. 49 and 50, the second swim being prolonged in an incline to the draining pens. Such a vat may be constructed as follows:

Build an oblong tub 15 feet long, 5 feet deep, 5 feet wide at the top, and 3 to 5 feet wide at the bottom. Running lengthwise through the center, build an upright, partially open, partition 10 feet long and 44 feet deep (measured from the top of the tub), leaving an open space of 2 feet at each end and 6 inches at the bottom; this partition is supported by three uprights running to the floor of the tub, and cross supports may be placed on top of the tub at any point except near the entrance of the swim. A gate is hung at one end between the slide (entrance) and the incline (exit), and should extend above the tub, in order to prevent the sheep from jumping over the middle partition into the second swim; it should extend down to within about 6 or 12 inches of the floor of the tub. When this gate is closed against the middle partition the sheep will leave the vat by the incline to the draining pens; when it is closed against the incline, the sheep can be forced to swim around the tub two or three times, as desired. Or, in place of a swinging gate, two sliding gates may be arranged to run up and down in grooves, balancing each other or each balanced separately by weights. One of these gates is placed between the end of the vat and the end of the middle partition, the other is placed at the entrance of the incline to the draining pens.

By constructing the double vat and sending the sheep around three times there would result, first, a saying in the original cost of the tank when compared with a 90-foot straight swim; second, a saving in space; third, less than half as much dip would have to be kept warm at a time; fourth, less than half as much dip would have to be made up at a time; fifth, the residue after dipping would be reduced