Feeds and Feeding: a Hand-book for the Student and Stockman (1906) p. 615-616
By William Arnon Henry

935. Corn-cob charcoal.

Corn cobs are abundant in districts where swine feeding is largely practiced. They can serve no better purpose so far as needed than in producing charcoal for use in the feeding pens.

1Farm, Stock and Home, July 15, 1894.

The following directions for reducing cobs to charcoal are given by Theodore Louis,1 a breeder of high repute in the Northwest: "Dig a hole in the ground five feet deep, one foot in diameter at the bottom and five feet at the top, for the charcoal pit. Take the corn cobs, which have been saved in a dry place, and, starting a fire in the bottom of this pit, keep adding cobs so that the flame is gradually drawn to the top of the pit, which will be thus filled with the cobs. Then take a sheet iron cover, similar to a pot lid in form, and over five feet in diameter, so as to amply cover the hole and close up the burning mass, sealing the edges of this lid in turn with earth. At the end of twelve hours you may uncover and take out a fine sample of corn-cob charcoal."

Charcoal so produced may be fed directly, or, better still, compounded as directed by Mr. Louis in the following manner:

"Take 6 bushels of this cob charcoal, or 3 bushels of common charcoal; 8 pounds of salt; 2 quarts of air-slacked lime; 1 bushel of wood ashes. Break the charcoal well down, with shovel or other implement, and thoroughly mix. Then take 1 1/4 pounds of copperas and dissolve in hot water, and with an ordinary watering pot sprinkle over the whole mass and then again mix thoroughly. Put this mixture into the self-feeding boxes, and place them where hogs of all ages can eat of their contents at pleasure."

Where corn cobs are burned for fuel in the prairie districts the ashes should be saved for the pigs.