Illustrated Companion to the Latin Dictionary/Amussis

This article incorporates text from a publication now in the public domain: Rich, Anthony (1849). The illustrated companion to the Latin dictionary, and Greek lexicon. p. vi. OCLC 894670115. https://archive.org/details/illustratedcompa00rich. 

AMUS'SIS. An instrument employed by masons and builders for testing the evenness, accuracy, and regularity of their work, as the rule, the square, and the plummet is by carpenters. The exact meaning is somewhat doubtful; for, from the different passages where the word occurs, it appears to have been equally applied to a level for testing the uniform evenness in the surface of a wall or course of masonry (Festus. s. v. Amussim and Examussim. Varro. ap. Non. s. v. Examussim, p. 5. Mercer); the square for proving a right angle (Auson. Edyll. xvi. 10.); and the line and plummet for preserving an exact perpendicular (Sisenna ap. Charis. ii. p. 178.); but in each case the same general use and notion is preserved, that in whatever way applied, it is always for the purpose of proving that the work is accurately and regularly done: whence the expression adamussim or examussim is equivalent to accurately, i. e. according to line and rule. Macrob. Sat. i. 4. Aul. Gell. i. 4. 1.