PAEASITIC DISEASES OF THE SKIN. 251 



Cbc Catching pen. 



This should connect with a large pen, made to hold 1,000 

 head of sheep, from which they are driven into the catching pen, 

 which is built as follows : 



Its floor is raised eighteen inches above the ground, to be 

 on a level with the sides of the dipping vat, which project about 

 that distance above the ground; its size, to be convenient for 

 catching sheep, should not exceed twelve feet by twelve feet. A 

 gate is placed at the end communicating with the large pen, the 

 sides are boarded up for about three feet in height, an opening 

 two and one-half feet wide being left where the vat and pen join. 



Cbc Vat. 



The vat should be at least fifty feet long, the other 

 dimensions the same as those previously given. It should be 

 built of two-inch grooved pine lumber, well leaded in the seams 

 when put together, to make it absolutely water-tight. It is sunk 

 in the ground to a depth of four feet, so that it projects not to 

 exceed eighteen inches above the gTound; the sides should be tied 

 to beams sunk in the earth, level with the bottom of the vat, to 

 prevent the outside pressure causing the sides to bulge in and 

 make it too narrow. The end of the vat next to the catching 

 pen is made perpendicular, while the end leading to the drain- 

 ing pens is made to slant at an angle of forty-five degrees, with 

 strips nailed across to form a ladder for the sheep to climb out on. 

 Length of vat on surface fifty feet. Length at bottom forty 

 feet. 



The draining pens are of great importance, as they effect a 

 large saving in dip. They should be built as per the illustra 

 tion, the plan being to build one large pen twenty feet by twenty 

 feet square, having a slope of one foot from back of floor to end 

 of vat, the sides sloping towards the center, with about six 

 inch pitch from side of pen to center. In the center is a gutter 



