This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
An ironing board that had been used on two chairs was cut off square on one end and a piece of heavy sheet metal cut and bent into the shape shown in Fig. 1. The square end of the board was fitted into the socket formed by the sheet metal. After attaching the socket to the wall with screws the board was easily put in place as shown in Fig. 2. The brace is hinged to the under side of the board. - Contributed by L. G. Swett, Rochester, N. Y.
Ill: Socket and Manner of Holding Board