NAUTICAL ANTIQUE BRASS MARINE COLLECTIBLE. from a reference plane was widely used by mariners to estimate distances on the sea.
Theodolite With Compass - Brass Alidade Transit Telescope Survey Instrument
Nautical Brass Binoculars Antique Finish Vintage Gift Telescope Leather
Elegant 6" Antique Brass Telescope - Leather-Bound with Teak Presentation Box
