It is clear from medieval illustrations published by Salzman that relatively few hand tools were noticed on building sites by the illustrators. Examination of various early wooden structures, and the recent detailed examination of an intricate and accurately cut mid-13th-century scarf joint have, in general terms, confirmed this. Other types of carpentry work, such as the construction of door leaves, suggest the existence, before 1066, of special hand tools designed to rebate and rout-out housings of even depth such as exist in the Westminster Abbey door leaf. The superiority of early tools lay in their sizes and weights, which were strictly commensurate with the work required. The possibility of a water-powered medieval factory for vee-edged boarding and mechanized plank edge cutting also exists.