mainspring
(ˈmeɪnsprɪŋ)
[main a. 8 b.]
1. A principal spring in a piece of mechanism. a. In a gun-lock, the spring which drives the hammer. (Also fig.)
| a 1616 Beaum. & Fl. Custom of Country iii. iii, Hee's foule i'th touch-hole; and recoiles againe, The main spring's weakned that holds up his cock. 1824 P. Hawker Instr. Yng. Sportsm. (ed. 3) 42 The mainspring to be well regulated should at first pull up very hard. 1828 Scott F.M. Perth vi, How now, Smith, is thy mainspring rusted? |
b. The principal coiled spring of a watch, clock, or other piece of mechanism.
| 1591 Sylvester Du Bartas i. vii. 162 God's the main spring, that maketh every way All the small wheels of this great Engin play. 1763 T. Mudge Th. Improv. Watches (1799) 12 The wheel that communicates the force of the main-spring to the balance. 1830 Kater & Lardner Mech. xiv. 195 In watches and portable chronometers,..a spiral spring, called the mainspring, is the moving power. 1869 Noad Electricity 381 Levers are released, and the machinery of the telegraph worked by mainsprings, are [sic] left free to rotate. |
2. fig. The chief motive power; the main incentive.
| c 1695 J. Miller Descr. New York (1843) 30 It being proposed that the bishop himself who shall be sent over be the main-spring and mover in this work. 1799 Nelson 21 Apr. in Nicolas Disp. (1846) VII. p. clxxx, I am here the mainspring which keeps all things in proper train. 1823 Byron Juan ix. lxxiii, Some heathenish philosophers Make love the main-spring of the universe. 1850 Merivale Rom. Emp. (1865) I. i. 23 The cupidity which animated individuals was..the mainspring of the political factions of the time. 1888 Burgon 12 Gd. Men II. x. 287 Truth..was the very mainspring..which actuated everything he thought, or said, or did. |
3. attrib., as mainspring cramp (in a gun-lock), mainspring hook, mainspring punch, mainspring winder (in a watch).
| 1844 Regul. & Ord. Army 96 note, One Main-Spring Cramp. 1884 F. J. Britten Watch & Clockm. 165 Main Spring Hook..Main Spring Punch..Main Spring Winder. |