A thick, shaped brass plate, elaborately decorated with foliate patterns and sea monsters, has an inverted 'T' slot, a shackle and suspension ring above, and a heavy round brass weight below. Secured by steel screws to either side of this brass plate are two substantial steel bars terminated by edge sights. The vertical part of the inverted 'T' slot has a scale on either side 0 to 60, divided to 5, subdivided to 1, numbered by 5, and a similar scale is beside the horizontal slot 65 to 0 to 65. These slots once accommodated some sighting arrangement, now missing, for measuring inclination.
