trick wheel. Wood disks may be sawed out by use of any band, coping or jig saw, and need not be perfectly round. The trick wheel is small, and the adult hamster gets his fun on the outside of the wheel, climbing up the side of the pen to mount the wheel; or climbing the outside of the wheel. A 31⁄2 inch tread of No. 4 or No. 6 hdw. cl. is tacked to the edge of this 5 inch wood disk. Ends of hdw. cloth tread should overlap approximately 1⁄2 inch to permit smooth weaving in or tying of the wire ends. No sharp edges should protrude from the outer side of the hdw. cl. tread. Trim off the sharp points; or, better still, use the selvage edge, which will strengthen the wheel. The hub (Jib) of this wheel is 3⁄4 inch above center (C), and wheel is mounted to the side or partition of pen by means of a screw or small bolt (5). Illus. 43 shows side view of wood disk with a large washer (W2) between disk and partition to permit more free action of wheel, and a somewhat smaller washer (W1) on the tread side of wheel to prevent head of screw or bolt cutting the wood. This wheel may be mounted so that its bottom is from 11⁄4 to 21⁄2 inches off the floor. Illus. 42 shows wheel mounted 21⁄2 inches from floor. If 11⁄2 inches off floor, young from the 16th day onward may benefit by climbing into and upon this wheel which uses less pen space than any other wheel. If free running of wheel is desired, simply make the hub (Jib) at center (C). If one desires a wheel taking even less pen space, the hdw. cl. tread stripping may be only 2% inches wide. The screw or bolt mounting this trick wheel should be back about 7 inches from front end of partition to allow clearance of front climbing strip (CS) and easy servicing of the pen.
Of all hamster wheels, the author favors the 8 inch exercise or tread wheel shown in Illus. 44, 45 and 46. The hub is at center as in Illus. 44 so that the wheel turns freely. A small piece of metal tubing (Tb, Illus. 45) may make a better hub. Washers (W) are used same as in trick wheel mounting. Illus. 46 shows wheel mounted in pen, and (a) shows bottom clearance in pen 10 inches high as approximately 11⁄4 inches. It is just as well to mount this wheel with 11⁄2 inch floor clearance since animals use the inside of wheel and young may begin treading or turning it from the 16th day. If preferred, a hdw. cl. tread of 21⁄2 to 3 in., instead of 31⁄2 in., may he used in pens 8 in. wide. If pens are 12 in. high inside, as (b) in Illus. 46, wheel
