A very unusual transparent pocket compass, difficult to date, but probably from c.1890-1930. This type of compass was intended to be used with a map, with features such as roads and obstacles being visible through the glass. F. Barker & Son made various transparent compasses, often known as cyclists or riders compasses, during the late 19th and early 20th centuries. In J. H. Steward catalogues of the time they were described as 'An excellent horseback compass, and if held above the head the needle can be seen at night time against the sky. If laid on a map, being transparent, the direction of roads can readily be seen'. But Barker's designs were rather different and all featured an English bar needle, wheras this compass has a blued needle of the kind often seen in late Victorian and Edwardian compasses c.1890-1910. The compass case is brass, with a transit lock operated by a sliding button. On one side of the compass the glass is bevelled, the other side is flat.
The compass is in good condition and finds North very well. The transit lock is working, but is a little stiff, and probably best left unlocked. This has no adverse effect on the compass, which is otherwise in excellent working order.