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.
As children must hold tickets for theaters the same as adults, but the ordinary chair is too low to permit a child to see the performance, an auxiliary seat such as shown in the sketch would sometimes be desirable as it elevates the child so its head will be on a level with those of other spectators. The seat is made of a strip of canvas with eyelets for wire hooks that fit over the arms of the ordinary theater chair. It is necessary to have extra eyelets at one end of the canvas to adjust it to varying widths of seats. - Contributed by W. A. Jaquythe, Richmond, Cal.
Ill: Seat in a Theater Chair