Scroll. 1.
(Joinery.) An ornament of a form derived from, and yet distantly resembling, a partially unrolled scroll of parchment. Instruments are made for laying out scrolls and curves for stair-work, and other irregular forms. See spiral, instrument for drawing.
2. (Hydraulic Engineering.) A spiral or converging adjutage around a turbine or other reaction water-wheel, designed to equalize the rate of flow of water at all parts around the circumference of the wheel, by decreasing the capacity of the chute in its circuit. See turbine. A double scroll is seen in the cut, the valves of each being operated by a single rod, and two worms meshing into the segment-racks of the valve-stems. marked in position and then cut to match the inequalities.
Scribing-iron. |
Scribing-compass. |