| 释义 |
tractory, a. and n. rare.|ˈtræktərɪ|
[ad. L. tractōri-us of or for drawing, f. tract-, ppl. stem of trahĕre to draw: see -ory.]
†A. adj. Serving for traction; tractive. Obs.
1684tr. Bonet's Merc. Compit. x. 368 He shews the various uses of his..tractorie Machine which he invented.
B. n.
†1. Old name for some part of a plough: see quot. Obs.
[1607J. Carpenter Plaine Mans Plough xiii. 109 Now..let vs first consider of the Soule, which is that Instrument wherewith being fastened to the Oxen, the Husbandman rippeth vp his land for the Seede. ] Ibid. xviii. 127 (heading) The 5. part of the Soole, is the Tractorie.Ibid. xxvii. 160 The Tawe, or that yron Rope which embracing the Beame, assureth it to the Tractory.
†2. Ch. Hist. = tractatory n. Obs.
1709J. Johnson Clergym. Vade M. ii. 179 If they cannot come, to write their excuse in the Tractory. 1725[see tractatory].
3. Geom. = tractrix.
1820G. Peacock Examples Diff. Calc. i. xxiii. 174 The mechanical tractory of a straight line upon a perfectly smooth plane is an inverted semicycloid. 1853Glynn Power Water 140 Mr. C. Schiele of Oldham..is the proprietor of this mill, and the curve he has adopted is one discovered by Huygens, in his investigation of the cycloid. It is one of those singular and beautiful curves called ‘tractories’, and in this case it is produced by drawing the centre point of a radius bar along a straight line, which is the axis of the curve. 1864Webster, Tractory, Tractrix, the curve described on a plane by a heavy point attached to a string, and drawn along by moving the other end of the string. |