▪ I. penstock1
(ˈpɛnstɒk)
[f. pen n.1 + stock n.]
1. A sluice or flood-gate for restraining or regulating the flow from a head of water formed by a ‘pen’ (see pen n.1 3), as in a water-mill.
| 1607 Cowell Interpr. s.v. Bay, Water comming out of them by a passage or flud-gate (called the penstocke). 1725 Lond. Gaz. No. 6420/3 A Penstock of a Pond. 1801 Trans. Soc. Arts XIX. 268 The penstock, which regulates the quantity of water running to the wheel. 1864 Daily Tel. 26 July, There are sixteen openings..through which the sewage flows into the reservoirs as regulated by the penstocks—or floodgates. |
| attrib. 1791 R. Mylne Rep. Thames & Isis 52 Two ten ft. Bridges to a Penstock ditch. 1861 Times 7 Oct., The penstock-chamber, tide flaps, and overflow channel at the junction of the High Level, the Middle Level, and the Outfall Sewers are works of magnitude and interest. |
2. a. (orig. and chiefly U.S.) The channel or trough in which a penstock (in sense 1) is placed: = pentrough. b. A tube by which water is conveyed from a head of water into a turbine. c. Also applied to the barrel of a pump, through which the water passes up.
| 1799 Trans. Amer. Philos. Soc. IV. 349 Let ABCD Fig. 1 represent a large cistern or penstock, and MKLN an orifice made in one of its sides. 1828 Webster, Penstock, a narrow or confined place formed by a frame of timber planked or boarded, for holding or conducting the water of a mill-pond to a wheel, and furnished with a flood gate which may be shut or opened at pleasure. 1864 Ibid., Pen-stock... 2. The barrel of a wooden pump. 1894 Pop. Sci. Monthly XLV. 613 A penstock..is a great tube, usually,..of boiler plate..conveying water under head into the wheel-case in which the turbine revolves. 1933 Discovery Apr. 110/2 The station is several miles below Niagara Falls, the water being led to the ‘pen-stocks’ (the tubes which guide the water to the turbines) by means of a concrete canal from a point above the falls. 1955 Times 14 May 13/1 With the expected completion in 1955 of a modern wood-handling system and major repairs to its older penstocks, the company will have reached the end of the rehabilitation programme. 1963 Weekly News (Auckland) 21 Aug. 27 Six parallel penstocks made from prestressed concrete will carry the water from Lake Benmore. 1965 E. L. Myles Emperor of Peace River i. xiii. 135 They whip⁓sawed lumber for the roof and the penstock flue [of a water mill]. |
▪ II. ˈpenstock2 rare—0.
[f. pen n.2 + stock n.]
A penholder.
| 1864 Webster, Pen-stock... 3. The handle used with a metallic or other pen. |