A narrow strip of hard wood, steel, or brass, with one edge cut perfectly straight, used to test the accuracy of a plane surface, or as a guide for a cutting instrument.
1812. P. Nicholson, Mech. Exerc., 142. The Straight Edge is a piece of stuff or board made perfectly straight on the edge, in order to make other edges straight.
1816. J. Smith, Panorama Sci. & Art, I. 24. A perfectly straight steel ruler, for which we shall adopt the technical term, by calling it a straight edge.
1879. R. Rouse, Sci. & Pract. Geom., 17. A straight-edge or ruler.
1907. J. A. Hodges, Elem. Photogr. (ed. 6), 106. An ebonite straight-edge.
b. Printing. (See quot. 1888.)
1888. Jacobi, Printers’ Vocab., 134. Straight-edge, a long wooden or metal stick used for squaring up the pages in a forme in order to obtain correct register in printing.
1890. W. J. Gordon, Foundry, 188. The machine had now the impression cylinder, the inking rollers, the straight-edge, and the travelling table of 1790.
