Caption from Forman's book Report from Red China: A company of the Min Ping with their home-made wooden cannon. The guns are made of elm logs, have a 3-inch bore and are loaded with stones and scrap metal. They are fired by a match-lock mechanism tripped by a long string. Print 1844 c1: Wooden cannon. Print 1844 c2: A company of Lin Tso's 'artillery' men with their fantastic wooden cannon. Sino-Jap War 1937-1945.