Elegant prismatic compass made of solid brass by Stanley London. This precise design was traditionally used for navigation, surveying, and scientific expeditions. The lid is engraved with a table of natural sines, useful for field goniometric calculations. The instrument features a foldable alidade with a sight slit, an engraved compass rose, and an integrated reading prism. It is in good overall condition with a beautiful patina on the brass. It functions well and is a fine example of an early scientific instrument that is both functional and decorative.