late 17th century, large dial plate engraved with two sundial projections, horizontal dial with folding gnomon and plumb bob, with chapter ring 4am to 8pm divided to two minutes, and a elliptical dial with vertical gnomon adjustable against a scale of date and solar declination, position of equinoxes indicating the Julian calendar, whole dial plate with four levelling screws and engraved to the reverse D 56.70, complete in original velvet lined sharkskin case, with an antique manuscript page of instructions copied from Stone's 1758 translation of Nicholas Bion's Construction and Principal Uses of Mathematical Instruments, dial plate 13x20cm Note The dial was designed for a latitude that runs from Dundee in the East to North Argyll in the West.