For the car axles we bought four 1/2-inch bolts, 6 inches long, with two washers and two nuts for each bolt. In each side of the car, about 8 inches from the ends, we nailed face blocks; that is, blocks of wood for the wheels to bear against. These face blocks were only 1/2 inch thick. Then in these blocks holes were drilled which were carried clear through the scantling. The holes were just large enough for the bolts to fit snugly in them. The bolts were inserted from the inside, so that their threaded ends projected out at each side of the car. A patch of wood was nailed to the scantling over each bolt head to prevent the bolt from slipping back into the car. Then the wheels were mounted on these bolts, which served as axles.

Fig. 298. The Car Wheel.