Miniature Francis Barker Singer's Patent Compass c.1870 Musketry In the mid-19th century the

In the mid-19th century the drum microscope was popularized by the instrument maker Georg Oberhausser

so that the divisions read 40 to 100mm and respectively 3 to 8 km

the Brunton Pocket Transit utilises magnetic induction damping rather than fluid to damp needle oscillation

jewellery cases

Miniature Francis Barker Singer's Patent Compass c.1870 Musketry In the mid-19th century theA miniature Singer's Patent compass, made by Francis Barker & Son c. 1870. There is a tiny Francis Barker 'Trade Mark London' logo within the star above the lyre at 'N'. This is a very small example of a Singer's Patent, at just 27mm diameter most brass cased Singer's were around 40 45mm. The compass has a paper card, brass box case with push fit lid, and flat glass. The compass card is hand drawn in the classic Singer's design, and marked 'Singers