Quadrant

Two nearly identical clinometers for measuring the maximum heel of a rolling ship. Both are made of brass, mounted on a wooden backing plate with the center of the arc at the top. The scale on the arc runs from 0° to 45° on either side. The outer edge of the arc is toothed, with teeth on each side facing in opposite directions. The two pointers have pallets on the back that engage with the teeth: this allows them to move only outward along the arc. The pallets can be manually released to reset the pointers to 0°. A small gap in the pallet edge prevents the pointers from occupying the same eighth of the arc. The teeth of the first quadrant (a) divide the arc into quarter degrees, while those of the second (b) divide it into half degrees. The pointers on the first quadrant (a) roll over the protractor with small rollers. When the ship rolled, each pointer swung out to the side toward which the ship heeled, indicating the maximum angle of heel. [combined description]