Description

Designed for use in plane table surveying and trigonometric triangulation, this all brass instrument is extremely unusual.

17 inches long, the alidades are fixed and blocked (similar to the supports used for sundial gnomens). The underside screws are stamped 3(3) and 4(4) so there was no confusion when assembled. Meant to be carried intact (the wooden case would have measured at least 18 x 8 x 2 inches), this instrument has seen little use. I believe it is military ( see stamps photo), no broad arrow but GLK with crown and date? 1875. The sighting and object vanes (object vane with dual openings) are of unusual construction as well. Having keyhole (figure 8) openings and instead of horsehair, full metal sights! The uprights (vanes) are over 7 inches tall and 1/8 thick. The base being 1/4 inch thick with full Gunter scales are bevelled edged, divided into inches and centimeters. A most robust and complex instrument. Unsigned but of the highest quality it has one tiny nick at the 5 inch mark on the edge.  The engraving is crisp and clean, NOT worn. It will be posted intact (don’t want to bruise the screws).