1870 D.R. Smith Magnetic Time Reader Compass

 Marked 'D.R. Smith Patent Aug 23 1870'.

Pocket compass sundial. Stamped brass case, glass dome, Floating compass with brass gnomon on paper dial face.  In use, the sundial naturally aligns to North and time is read on the dial. Designed to accurately display local solar time along  the 50° North Latitude ( London).  

This compass was used for timekeeping, navigation, and aligning with the sun's position to indicate local solar time. 

Weight: 0.6 oz.

Diameter: 1.5"

Height: 0.75"