It had two casings, an inner and outer one, including the door, and the interspace was filled in with charcoal, or wood, and treated with a solution of alkaline salt. 威廉·亨利·杜利特.世纪发明.
Matches are made round by one machine by pressing the block against a plate having circular perforations, and the interspaces are beveled so as to form cutting edges. 威廉·亨利·杜利特.世纪发明.