tractoryadj.n.

1684 tr. T. Bonet Guide Pract. Physician x. 368 He shews the various uses of his..tractorie Machine which he invented.

1607 J. Carpenter Plaine Mans Spirituall 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.]

1607 J. Carpenter Plaine Mans Spirituall Plough xviii. 127 (heading) The 5. part of the Soole, is the Tractorie.

1607 J. Carpenter Plaine Mans Spirituall Plough xxvii. 160 The Tawe, or that yron Rope which embracing the Beame, assureth it to the Tractory.

1709 J. Johnson Clergy-man's Vade Mecum: Pt. II 179 If they cannot come, to write their excuse in the Tractory.

1725 D. Cotes tr. L. E. Du Pin New Eccl. Hist. 17th Cent. I. v. ii. 69 They call'd those Tractatory Letters, by which the Metropolitans invited the Bishops of their Province to Synods... The Excuses of the Bishops who could not come to the Synod were wrote at the Bottom of the Letter which was sent to them, which they call'd Tractory, or Tractatory.

1820 G. Peacock Coll. Examples Differential & Integral Calculus i. xxiii. 174 The mechanical tractory of a straight line upon a perfectly smooth plane is an inverted semicycloid.

1853 J. Glynn Treat. 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.

1864 Webster's Amer. Dict. Eng. Lang. 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.