This dial for the National Trust at Cragside, the former home of Lord Armstrong, is engraved in gun metal, a form of bronze favoured by the Admiralty for making cannon (88% copper, 10% tin and 2% zinc).
The gnomon is in the form of the ‘trebuchet’ motif (a Roman war catapult) that Lord Armstrong designed for his personal use, the arm placed at the correct angle for telling local time.
sundials