Santa Claus

A hard-working Santa Claus is climbing a rope to the chimney. In reality it is his assistant who pulls the rope from the bottom and Santa Claus travels up without doing a hand's turn.

If we pull the string down Santa Claus' legs tighten on the rope and remain fixed, while the hands move up the rope. If we loosen the string, the hands remain fixed and the legs are pulled up by a rubber belt which goes round Santa Claus.

The principle of operation makes use of the differences in friction. The hands are tightened on the rope by means of a rubber band which presses them together. As far as legs are concerned, the string runs askew through a peg between the knees. In a bent position, the string is wrapped around the peg at an angle of almost 360°. The principle of wrapping the ship rope round the mooring peg used by seamen explains why friction force of the string round the legs is greater than the friction force of the hands. The legs remain motionless on the string while the hands move upwards.