[WELL sb.1]
1. a. An opening through a floor or series of floors, for a staircase, chimney-stack, or for the admission of light, etc.
1680. Leybourn, Primatt’s City & Country Purchaser, III. 187. Note … that … you do afterwards take the dimensions of the Well-hole for the Stairs. Ibid. (1690), Curs. Math., 901. In the measuring of flooring,… you must deduct out of it the Well-holes for the Stairs and Chimneys.
1791. Smeaton, Edystone L. (1793), § 42. A Well Hole was begun to be left upon these courses for stairs in the center.
1819. Rees, Cycl., Well-hole, in Building, is the hole left in a floor, for the stairs to come up through.
1892. Dict. Arch. (Arch. Publ. Soc.), Well-hole,… the opening through a floor or floors, in a large warehouse, whereby light can be obtained from a glass roof over it, to each floor.
b. The empty space round which the stairs of a winding staircase turn.
1823. P. Nicholson, Pract. Builder, 185. Stairs that have a well-hole, or hollow in the centre, are called geometrical stairs.
1825. J. Nicholson, Operat. Mechanic, 597. A cylinder … of the size of the well-hole of the staircase.
1833. Loudon, Encycl. Archit., § 423. The well-hole of the stair is shown at m.
c. A vertical passage-way (for machinery, a lift, etc.); a shaft.
1841. Brees, Gloss. Civil Engin., 297. Well-hole, a hole connected with some mechanical contrivances, and adapted for the reception of a counterbalancing weight, and for other purposes.
1862. Catal. Internat. Exhib., II. x. 5. The uprights or guides of the shaft or well-hole [of a lift].
2. The compartment at the lower end of a ship’s pump.
1774. Phil. Trans., LXIV. 412. If … plates of copper … were … continued down the main-top-gallant-mast, the main-top-mast, and part of the main-mast, into the well-hole.
