1684 P. Ker 3 I bent my Soul, and shot my Wit, Thinking this Center-Mark to hit.
?1792 J. Barrow 25 Place the center-mark of the protractor upon the point A.
1895 J. Fehrenbatch (1900) 735 Find the center between the two marks on the guide on that side and place a center mark there.
1933 P. Godfrey i. 15 He examines these things for himself before returning to his position on the down-stage centre mark.