Consists of a heavy black-painted brass dial plate, graduated to 360 degs with white markings. A circular bubble level is fitted to the dial, and at its centre is a clamp block to hold the semi-cylinder. The dial can be revolved within a securing bracket and can be clamped in any position. The bracket carries a white-painted lubber line. The semi-cylinder is of black-painted brass, rotates about its vertical axis and can be tilted for latitude. Time, date, and latitude scales are fitted. A swivel socket is fitted to house a gnomon which canbe inclined to allow for the sun's declination. In fitted wooden box 17.75 x 9.25 x 7.5" (45.1 x 23.5 x 19.0cm) containing spare semi-cylinder, six gnomons, three wing nuts, and circular bubble level.