I have been reading many old boxing books from the 1800s and early 1900s (some public domain books can be viewed on google) and I noticed there is little talk even in the "training" chapters on focus mitts. They will often mention what we call heavy bags but in the books I have seen there doesn't seem to be any reference to focus mitts. Is this because they are a relatively new addition to the sport of boxing?
Any info on the history, development of the focus mitt would be great.