[f. LAP v.2]
† 1. ? Something wrapped up; a bundle. Obs.
1673. New Jersey Archives (1880), I. 132. In token whereof they presented about 20 deer skins, 2 @ 3 laps of Beaver, and 1 string of Wampum.
2. The amount by which one thing overlaps or covers a part of another; hence concr. the overlapping part.
1800. Trans. Soc. Arts, XVIII. 377. Stopping the apertures between the laps of glass with putty.
1808. Pike, Sources Mississ., II. (1810), 194, note. Those logs were joined together by a lap of about two feet at each end.
1823. P. Nicholson, Pract. Build., 399. All kinds of slate have a lap of each joint, generally equal to one-third of the length of the slate.
c. 1850. Rudim. Navig. (Weale), 128. Laps, the remaining part of the ends of carlings, &c. which are to bear a great weight or pressure, such as the capstan-step.
1869. Sir E. Reed, Shipbuild., ii. 39. The laps of the outer keel-plate and garboard … require the usual double row [of rivets].
1895. Jrnl. R. Inst. Brit. Archit., 14 March, 351. The roof should have a lap of at least 31/2 inches of tiles.
1897. Daily News, 10 May, 5/5. The hand-made cigarette … having a smaller ‘lap.’
b. Half-lap: an arrangement for the joining of rails, shafts, etc., consisting in cutting away half the thickness of each of the two ends to be joined, and fitting them together. Also attrib.
1816. Specif. Losh & Stephenson’s Patent, No. 4067. 6. The half lap joinings of the rails.
1825. N. Wood, Railroads (1838), 42. [The rails] are now formed with a half-lap.
1875. Carpentry & Join., 71. The half lap dovetail … has this one advantage, that [etc.].
c. Steam-engine. The distance traversed by a slide-valve beyond what is needed to close the passage of steam to or from the cylinder.
1869. E. Malbon, in Eng. Mech., 3 Dec., 282/2. Ascertain if they have had equal lap on the steam and exhaust side.
1881. J. W. Aston, in Metal World, No. 18. 274. The amount that these faces overlap the steam-ports being termed the lap of the valve.
1895. Mod. Steam Eng., 38. The lap of the slide being equally divided.
d. U.S. ‘Any portion of a railroad track used in common by the trains of more than one system’ (Funk’s Stand. Dict., 1893).
3. Euchre. (See quot.)
1886. Euchre: how to play it, iii. 40. The Lap game may be played by two, three, or four persons, when they agree to play a series of games, so that the lap may be applied, which is simply counting upon the score of the ensuing game all the points made over and above the five of which the game consists.
4. A layer or sheet (usually wound upon a bobbin or roller) into which cotton, wool or flax is formed in certain stages of its manufacture.
1825. J. Nicholson, Operat. Mechanic, 381. The cotton is in this state called a lap.
1888. J. Paton, Wool, in Encycl. Brit., XXIV. 658. The wool [for felted cloth] is scribbled or carded out into a uniform lap of extreme thinness.
1890. W. J. Gordon, Foundry, 163. The scutcher turns out the fibre in a thick fleecy mat, or ‘lap,’ which is wound round a roller.
5. The act of encircling, or the length of rope required to encircle, a drum or wheel. Also, enough of silk, thread, etc., to go once round something.
1867. W. W. Smyth, Coal & Coal-mining, 163. A large vertical cylinder … 16, 18, or even 20 feet in diameter at the first lap of the rope.
1867. F. Francis, Angling, iv. (1880), 134. It should be tied by a lap or two of silk.
1888. Lockwood’s Dict. Mech. Engin., Lap … (4) a single turn of a rope or chain around a barrel.
b. Racing. One of the number of turns round the track, that are required to complete the course.
1861. Chamb. Jrnl., 23 Nov., 333. They had gone fourteen ‘laps’ (as these circuits are technically called).
1871. R. Burn, Rome, 297. The number of laps [of a race] was usually seven.
1884. Dickens’ Dict. Lond., 27/2. A running track, three laps to the mile.
1894. Astley, 50 Years Life, II. 155. Having measured off the requisite number of laps to the mile on the gravel walks in our kitchen-garden.
6. attrib. and Comb., as (sense 2) lap-butt, -carling, -dovetail, -dovetailing, -jointed; lap-weld sb. and vb.; (sense 4) lap-bobbin, -cylinder, -machine, -roller; (sense 5 b) lap-scorer, -sprint. Also lap-joint (see quot. 1847); † lap-yard, the part of a roll of cloth that forms the outside wrapper. Also LAP-STREAK.
1892. Daily News, 9 Sept., 6/1. The shell plating … is fitted on the *lap-butt principle.
1874. Thearle, Naval Archit., 47. When these carlings are required to resist an upward instead of the ordinary downward thrust, they … lap over the under side of the beams, in which case they are termed *lap carlings.
1851. Illustr. Catal. Gt. Exhib., 263. This felt or lap is delivered to a wooden *lap-cylinder.
1847. Smeaton, Builder’s Man., 89. Fig. 24 represents the pin part of a *lap-dovetail.
1825. J. Nicholson, Operat. Mechanic, 588. *Lap dovetailing conceals the dovetail, but shews the thickness of the lap on the return side.
1823. P. Nicholson, Pract. Build., 164. Folding doors, which meet together upon a *lap-joint.
1847. Smeaton, Builder’s Man., 93. In a lap-joint, that is, in lapping two pieces together, supposing them of equal thickness, half the substance of each should be cut away.
1874. Thearle, Naval Archit., 113. The bulkheads … are connected by single-riveted lap joints and butts. Ibid. Liners are required behind the stiffeners by the *lap-jointed system.
1879. Cassell’s Techn. Educ., IV. 209/1. Carding engines, *lap-machines or doublers [etc.].
1896. Westm. Gaz., 25 July, 5/2. At one corner outside the track a little shed is filled with the *‘lap scorers.’
1886. Cyclist, 25 Aug., 1174/1. Fenlon, by a fine *lap sprint, landed a winner by five yards.
1875. Knight, Dict. Mech., *Lap-weld (Forging), a weld in which the welding edges are thinned down, lapped, and welded.
Mod. Catal., The tubes are *lapwelded.
1733. P. Lindsay, Interest Scot., 93. No Part of it [Linen Cloth] worse than the *Lap-yard or outside Cover.
