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.
When cleaning clothes by boiling them in a boiler over a fire, fit in a false bottom to keep the clothes from touching the bottom. The false bottom should be perforated with holes, 3/8 -in. in diameter and 1 in. apart, over the entire piece. Fasten four legs, each about 2 in. long, to the under side to make a space between the bottoms. In washing, all that is necessary is to place the clothes in the boiler and boil them. The dirt will come loose and settle through the holes and on the boiler bottom.