A very good antique prismatic surveying compass by Elliott Brothers c1870 in lacquered brass case

Prismatic compass with 2⅜” hand drawn floating green card dial, the outer reversed scale from 0-360°, numbered every 10°, divided to every 1° and ½°. The centre with simple rose divided to cardinals and intercardinals, fleur de lys indicating north, the centre marked “Elliott Bros., Strand, London.” Jewelled suspension. Flat glass.

Contained in a lacquered brass spun case with convex-faced 45 degree oxidised brass reflecting prism with height (focus) adjustment, dust cover, and brass keeper. Folding sighting vane, stowed position activating the transit lock, momentary brake behind. Pushfit lid which doubles as a stand when fitted to verso.

Condition: The compass card crisp, floating freely and finding north easily, the transit lock and momentary brake working correctly. The glass clear, the folding sight and prism mechanisms smooth. The brass case in very good condition, with only a few marks. Indeed, this compass appears to have seen little use.

Comments: This Schmalcalder type prismatic compass was a high quality instrument for its time, used both by civilian and military civil engineers and surveyors. The Schmalcalder patent having expired in 1826, Elliott Brothers was amongst a number of firms who began to produce similar surveying compasses with the reflecting prism. See image of Schmalcalder patent of 1812.

A really lovely example of these mid-Victorian compasses.