22 BULLETIN 1078, U. S. DEPARTMENT OF AGRICULTURE. 



weighs about 27 pounds. It may be constructed as follows (see 

 Fig. 7): 



Use two 5-foot strips of strap iron 1J inches wide by J inch thick 

 for base; two f-inch steel rods, 8 feet long, for jaws; two 4-foot sec- 

 tions and two 6-foot sections of T Vinch steel spring wire (No. 6) 

 for coil springs; and 10 feet of 1-inch or 1-J-inch mesh woven-wire 

 poultry netting, 3 feet wide, of No. 16 wire, for the sides and bottom. 

 For tools, a f-inch drill, heavy pliers, hammer, wrench, and wire 

 shears are necessary. 



In the longitudinal base section of strap iron a hole should be 

 drilled in the middle and two side by side in each end, and in the 

 cross section a hole in the middle and one in each end. The ends 

 of the longitudinal and cross sections should be bent up at right 

 angles, 1J inches above the base. These two strips should then be 

 bolted together at right angles with a f-inch bolt through the middle 

 holes. By loosening this bolt the crossbar can be swung around 

 under the trap to make it narrow for carrying. Bend the two rods 

 for the trap jaws into an approximate semicircle with upturned ends 

 an inch long. Slip the ends into the two holes in each end of the 

 longitudinal base strip, leaving enough spring in the jaws to hold 

 them in place. 



Make coil springs of the two 4-foot pieces of spring steel wire by 

 winding the middle of each closely six times around a 1-| inch pipe, 

 and of the two 6-foot pieces, eight times around. This should be 

 done while cold, or if heated, the wire must be very perfectly re- 

 tempered. The straight ends of the wires can be heated and bent 

 out 1^ inches at right angles and these right-angle sections curved 

 sideways to clasp the trap jaws, with the 4-foot springs about 7 

 inches above the base and the 6-foot springs about 12 inches above 

 the base. One of the long coil springs and then one of the short 

 ones should be slipped over each end of the longitudinal base strip 

 before the jaws are inserted in the end holes (only one of each 

 pair of springs is shown in the illustration). After the jaws are 

 in place the two ends of the short spring should be crossed with 

 a strong tension and clasped around the jaws up about 7 inches 

 from the base, then the long ones above them. The coil springs are 

 light and give a quick, strong action to the jaws. A double-ended 

 jump-trap spring of strap steel between the jaws and bolted down 

 in the middle would have some advantages, but would add to the 

 weight of the trap. 



The wire mesh should be put on in five sections, one a foot wide 

 the whole length of the bottom of the trap and wired securely to the 

 longitudinal section; one on each side wired all around to the jaws 

 and hinged at the lower edge to a 5-inch strip, with its lower edge 

 again hinged to the piece on the bottom, so as to fold in as the trap 

 is opened. This leaves the sides slightly full and convex, giving the 

 closed trap a clamshell form with plenty of room inside for the 

 beaver. The side walls should not be too rigid, but can be given 

 ample play by being loosely hinged to the jaws and bottom strips. 

 Wire rings or S links may be used for hinging. Clasping hooks 

 on the edges of the jaws to lock them when the trap is sprung render 

 it possible to use these light-rod jaws instead of heavier material 



