A wonderful early Diptych Gnome string sundial compass in a box wood case.  The paper disc set in the lid of the box says "Slip the notch in the brass arm over the stud in the lid and put the compass on a level place, in such a position that the North point of the needle corresponds with the mark inside the compass box, the shadow of the cord will show the time. The sun dial shows solar or apparent time: but a clock should be set to equal or mean time, in the above equation table the difference is stated in minutes. F means that the clock should be faster than the dial S slower.
Early to mid 1800's.
Item is not signed, but the hidden hinge tabs and the check-mark shaped clasp hooks were only ever used by F. Barker & Son prior to 1875. The dial is also a very typical Barker dial.