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 barrel that is water-tight and mount it on a shaft so that it runs between standards like a barrel churn. Fill the barrel about half full of walnuts, cover them with water and throw in a small quantity of gravel as grinding material. Close the opening tightly and turn the barrel for about 20 minutes. The walnuts will come out clean and smooth as glass. - Contributed by Arthur Seufert, The Dalles, Oregon.
When gathering my winter supply of walnuts, I found that they could not be hulled readily by hand. Not knowing of any machine designed for the purpose, I tried running them through a corn sheller and found it to do the work nicely. The sheller not only hulled them, but separated the nuts from the hulls, the nuts being carried out through the cob opening and the hulls dropping through the grain spout. - Contributed by Irl R. Hicks, Hallsville, Mo.