Here’s a rare shot of Jack Dempsey hitting the bag in Chicago for an exhibition match vs. “Kingfish” Levinsky, in February of 1932. There’s hundred of training shots of Jack Dempsey in various gyms all over the country during his boxing career but this one is unique — what’s that in the corner? — a pair of Milo Kettlebells! It is unclear if the champ every used them, however.

Also notable is the “wrist machine” on the right — a piece of equipment that used to be found in every boxing gym in the land but has all but disappeared today.