A good 6 inch ebony parallel rule by DARGUE BROTHERS of Halifax.

Marked 'DARGUE BROTHERS LTD HALIFAX'.

Also stamped '1918' with the Broad Arrow or Crows Foot military mark.

Bevelled edges to both rules, there is a small crack to the left lower rule, please see close-up images.

1¹/₄ by 6 inches overall when closed.