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 tightening the ankle rod with a nut on the upper end, so as to regulate the friction on the bolt and to compensate for any wear that may take place at the joint. This is recommended as being the strongest and most serviceable of the wooden feet. No. 218.

A New Foot with Rigid Ankle

This is not properly a rubber foot, but a modification of the so-called rubber foot suggested by improvements on our foot. In the construction of the old-style rubber foot a wooden core is covered with rubber and properly cured or vulcanized by heat. It is impossible to strengthen or reinforce this wooden core with a covering of rawhide as is done on the other parts of an artificial leg, because the heat necessary in vulcanizing the rubber burns and ruins the rawhide. This is obviated by the method of construction of this new foot.

The upper part of the foot is firmly attached to the ankle part by a pin, and the entire wood part is covered with rawhide. Thus the upper part of the foot forms practically one piece with the ankle, and strength is gained without adding weight. The sponge-rubber removable sole is fitted into a recess channeled in the foot and is securely held in place by one screw. No rubber is used at the top of the foot, but more is used on the sole where it is most needed.

If a foot needs be made extremely light a fine quality of felt is used in place of the rubber. The felt does not give as much spring and elasticity to the tread of the foot as the sponge rubber, and nothing is gained by using it except reduction in weight.

To prevent wear at the part corresponding with the toe joint of the natural foot, layers of