About this objectA Navigation Prismatic Compass otherwise known as a marching compass for fixing a setting for direction of a march.
Comprising brass cylindrical case with gauge on outside, hinged lid with circular glass window off centre. Mother of pearl outer gauge under glass with yellow arrow.
On back a circle of rubber
MakerE R Watts & Son
Place MadeLondon, UK
Medium and MaterialsBrass, mother of pearl, glass
Inscription and MarksOn front - 'VERNIER'S PATTERN'
On back - E R WATTS & Son/ LONDON/ No. 920/1909