Lot Essay
The pointers on the central joint appear to indicate a degree of fine adjustment in the laterally-pivoted point, probably controlled by a screw (now missing)
Details
An unusual brass transfer caliper, with internal/external jaws to one end, the other with scribing points loaded respectively longitudinally and laterally, with two indicator scales on centre point and screw stop --9in. long, signed Josh. Ridley, Inventor, early 19th century. See Front Cover Illustration