This instrument consists of two sets of parallel arms joined by a triangular joint midway. At one end is a pivot and clamp attached to a mounting bar, 36.3" (92cm) long. At other end is a graduated dial to 360 degs. mounted on a perspex plate 12" x 4" (30.5 x 10.1cm) which can revolve in azimuth. Made in brass
Parallel bars-11" (28cm) and 9" (22.9cm) long