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.
Procure a piece of flat iron similar to an iron hoop, bend it, as shown in the sketch, to make a piece 3 in. long and 1 1/4 in. wide and file one edge smooth. Sprinkle some fine lake sand over the glass, dampen the sand and rub the smooth edge of the iron band over the glass. It requires only a short time of rubbing to produce a beautiful frosted surface on the glass. - Contributed by M. E. Duggan, Kenosha, Wis.
Ill: The Filed Edge on the Coiled Metal Retains the Sand Particles as It is Rubbed over the Glass Surface