Also spirit level. [f. SPIRIT sb. + LEVEL sb. 1.] A kind of levelling instrument for determining a horizontal line or surface, usually consisting of a hermetically sealed glass tube filled with spirit and an air-bubble, which, when the tube lies exactly horizontal, occupies a position midway in its length.
1768. Phil. Trans., LVIII. 286. The spirit level shewing the axis of the telescope to be horizontal.
1793. Smeaton, Edystone L., § 97. It could be brought justly horizontal by means of a pocket Spirit-Level being placed upon it.
1805. R. W. Dickson, Pract. Agric., I. 292. This is to be done by means of levelling, in which the instrument called the spirit-level may be thus employed.
1834. Brit. Husb., I. 534. The instrument called a spirit or water level is the most proper for ascertaining the inclination of the ground with certainty.
1881. Young, Ev. Man his own Mechanic, § 282. 111. In bringing horizontal bars, shelves, etc., to a true level the spirit level must be used.
attrib. 1868. in Rep. to Govt. U.S. Munitions War, 135. Two degrees of elevation taken with a spirit-level quadrant.
Hence Spirit-levelling vbl. sb.
1861. Sir H. James (title), Abstract of the Principal Lines of Spirit Levelling in England and Wales.
