[From the name of the inventor, Paul Vernier (1580–1637), a French mathematician, who described it in a tract on the Quadrant Nouveau de Mathématiques, published in 1631.]
1. A device, consisting of a short movable scale, by which more minute measurements may be readily obtained from the divisions of the graduated scale of astronomical, surveying or other mathematical instruments to which it is attached.
Sometimes erroneously called a Nonius (q.v.).
1766. Instruct. for Hadley’s Quadrant, 17. A scale of divisions graduated on the chamfered edge or sloped side of the index, which scale is called the vernier.
1774. M. Mackenzie, Maritime Surv., 28. It would likewise be an Advantage if the Vernier was made to give every Minute of a Degree, in place of four or five, as in most Theodolites.
1798. Phil. Trans., LXXXVIII. 473. Another small slip of ivory is placed at each end of the arm, serving as a vernier, and subdividing these divisions into five parts.
1815. J. Smith, Panorama Sci. & Art, II. 26. The scale of variation is furnished with an instrument called a vernier or nonius.
1856. Kane, Arct. Explor., I. xiii. 144. Though I had much clear weather we barely succeeded by magnifiers in reading the verniers.
1888. Rutley, Rock-Forming Min., 18. For very exact work, the circle may be divided to half degrees, and a vernier may be employed.
2. attrib. and Comb., as vernier circle, division, piece, plate, scale, etc.
Also with the names of instruments or tools having a vernier scale or attachment, as vernier caliper, compass, transit (Knight, Dict. Mech.).
1788. Encycl. Brit. (ed. 3), II. 587/2. The first division of the vernier piece marked 15. Ibid. (1797), XVIII. 644/1. Vernier scale, a scale excellently adapted for the graduation of mathematical instruments.
1843. Penny Cycl., XXVI. 267/1. In order to read off the hundredths of an inch which the vernier zero advances beyond any tenth in the scale, we have merely to see what vernier division comes nearest to a division of the scale.
1862. Catal. Internat. Exhib., Brit., II. No. 2947. The vernier plate is carried on four arms, and a diagonal brace. Ibid. The horizontal limb, vernier circle, &c.
1884. Knight, Dict. Mech., Suppl. 925/2. Vernier Scale sight (Rifle), a hind sight with a vernier scale for accurate adjustment.
1884. F. J. Britten, Watch & Clockm., 148. To the bottom of the stock of a Vernier slide gauge he attaches a spring.
