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.
Do not discard the sandpaper stick or pencil sharpener used by a draftsman just because all the abrasive sheets have been removed. Make use of it indefinitely by fitting a wedge in one edge, as shown in the illustration, to hold fresh sheets of sand or emery paper. The wedge should fit tightly so that the ends of the abrasive sheet, when wound around the block, will be held tightly. Worn sheets can thus be removed and new ones applied when necessary. - Contributed by Chas. J. La Prelle, Flushing, L. I.
Ill: A Wedge Attachment for a Pencil-Sharpener Stick for Changing the Sheets of Abrasive