Term: Calks (logging)
Short, sharp spikes set in the soles of shoes. River drivers used them to keep from slipping off logs when they had to ride the logs down streams. Same as caulks, corks. View more information about logging elsewhere at wisconsinhistory.org
View pictures relating to logging at Wisconsin Historical Images.
[Source: Sorden, L.G. and Isabel J. Ebert. Logger's Words of Yesteryears. (Madison, 1956).]