[L.]
1. Rom. Antiq. a. The crooked staff borne by an augur; an augural wand. b. A curved trumpet, a clarion.
[1579–80. North, Plutarch, Camillus (1595), 159. They … did finde … Romulus augures crooked staffe…. This staffe is crooked at one of the ends, and … they call it Lituus.]
1611. Coryat’s Crudities, Panegyr. Verses, l i b. (Note) The Augures lituus or bended staffe.
1776. Burney, Hist. Mus., I. 518. A double Lituus. The lituus was a crooked military instrument, in the form of the augural staff, whence it had its name. It was a species of Clarion, or octave Trumpet.
1801. A. Ranken, Hist. France, I. I. ii. 334. The lituus of the Roman augurs became the crosier, or bishop’s staff.
1851. D. Wilson, Preh. Ann. (1863), I. II. iii. 368. A lituus or musical wind-instrument found in 1768.
2. Math. (See quot. 1839.)
[a. 1716. R. Cotes, Harmonia Mensurarum (1722), 85. Hujus generis alteram hic adjungam Spiralem, quam Litui Figuram appello propter formæ similitudinem.]
1758. Lyons, Fluxions, iv. § 119. If BF is inversely as the square of SP, the curve is called by Mr. Cotes the Lituus.
1839. Penny Cycl., XIV. 58. Lituus, a name given to a spiral thus described:—Let a variable circular sector always have its centre at one fixed point, and one of its terminal radii in a given direction. Let the area of the sector always remain the same; then the extremity of the other terminal radius describes the lituus. The polar equation of this spiral is r2θ = a.
3. Zool. A genus of cephalopods, now called Spirula; a shell of the genus.
1753. Chambers, Cycl. Supp., s.v., The lituus is always a conic shell, running in a strait line from the mouth, through a great part of the length, and from the end of this strait part to the extremity, twisting into the shape of a cornu ammonis. Ibid., Lituites, a name given to the stones formed in the lituus-shell.
