Vessel construction in the nineteenth century started with wooden models. Built to disassemble into pieces, the carefully shaped models would be taken apart and measured, and the measurements would be used to create full-sized patterns for fabricating the vessel's components. If drawings were created at all, they too were based on measurements from models.
Hosley claimed his "ship's model measurer," with its pair of ruled scales and easily adjusted calipers, provided greater accuracy, greater speed, and greater ease of use than ordinary measuring devices.
A notice praising Hosley's device appeared in Scientific American while his patent application was still pending. "By means of this instrument...the ship builder obtains those necessary measurements which will enable him to construct a vessel in a much shorter space of time than can now be done by any means in use for that purpose. This is a very useful and beautiful invention indeed, and one which cannot fail to come into general use in a very short time." No records have yet been found to indicate the measurer's manufacture or widespread use.
Abijah S. Hosley, Ship's Model Measurer, U.S. patent no. 8,307, Aug. 19, 1851.
"Ship Measurer," Scientific America, vol. 6, no. 36 (May 24, 1851), 284.