Antique solid brass carriage for a large beam or trammel compass. This is made to use a wood or brass beam and is either the pivot point or the scribe end for laying out a curves and circles. This compass head measures about 3 1/2" long overall. The iron compass spike measures about 7/8" long and over 1/8" across at the base. This is made for a beam that measures about 3/4" to 7/8" (this is adjustable with the clamping screw) and 1/4" thick.
This has a lovely patina of age.