Throne
The throne is of the compass bearing type
with s-shaped scroll work support(s). The throne is attached
with a integrated base. bears an unmarked compass.
Ring
The ring is of the simple, round cross-section
type (i.e. simple plain ring made from a round rod or piece
of metal). attached to ball-shaped
pin
Shackle
Shackle of the other type (i.e. unusual or
unique shackle). complex and pivots on a
pin which
is attached to a disc that pivots coplanar with the
instrument.
Mater
The mater and limb are of two pieces, soldered
and riveted construction. Large sighting vanes on the
horizontal axis, screwed to the outer edge of the limb, with
slotted sights. Scales on the limb: