Two derricks for stacking hay, that are used extensively in the alfalfa districts of Idaho, are shown in the illustration, Figure 151. The derrick to the left is made with a square base of timbers which supports an upright mast and a horizontal boom. The timber base is sixteen feet square, made of five sticks of timber, each piece being 8 x 8 inches square by 16 feet in length. Two of the timbers rest flat on the ground and are rounded up at the ends to facilitate moving the derrick across the stubble ground or along the road to the next hayfield. These sleigh runner timbers are notched on the upper side near each end and at the middle to receive the three cross timbers. The cross timbers also are notched or recessed about a half inch deep to make a sort of double mortise. The timbers are bound together at the intersections by iron U-clamps that pass around both timbers and fasten through a flat iron plate on top of the upper timbers. These flat plates or bars have holes near the ends and the threaded ends of the U-irons pass through these holes and the nuts are screwed down tight. The sleigh runner timbers are recessed diagonally across the bottom to fit the round U-irons which are let into the bottoms of the timbers just enough to prevent scraping the earth when the derrick is being moved. These iron U-clamp fasteners are much stronger and better than bolts through the timbers. [Illustration: Figure 151.--Idaho Hay Derricks. Two styles of hay derricks are used to stack alfalfa hay in Idaho. The drawing to the left shows the one most in use because it is easier made and easier to move. The derrick to the right usually is made larger and more powerful. Wire cable is generally used with both derricks because rope wears out quickly. They are similar in operation but different in construction. The base of each is 16 feet square and the high ends of the booms reach up nearly 40 feet. A single hayfork rope, or wire cable, is used; it is about 65 feet long. The reach is sufficient to drop the hay in the center of a stack 24 feet wide.] [Illustration: Figure 152.--Hay Carrier Carriage. Powerful carriers are part of the new barn. The track is double and the wheels run on both tracks to stand a side pull and to start quickly and run steadily when the clutch is released.] [Illustration: Figure 153.--(1) Hayfork Hitch. A whiffletree pulley doubles the speed of the fork. The knot in the rope gives double power to start the load. (2) Rafter Grapple, for attaching an extra pulley to any part of the barn roof.]