English

Alternative forms

• touch-mark

Noun

touchmark ‎(plural touchmarks)

1. (archaic) The manufacturer's official identifying sign, impressed into a pewter object.^[1]
   • 1988 Dec. 1, Susan G. Sawyer, Photog Pewter the Time-Honored Way," New York Times (retrieved 5 July 2012):

     For quality control, Parliament in 1503 required all London-made pewter to be stamped with the maker's symbol or touchmark.

2. (archaic, rare) A symbol, sign, or other inscribed indication used to aid the alignment, calibration, or other adjustment of a measuring device or scientific instrument.
   • 1876, W. H. H. Hudson, "On Observations made at San Antonio on the Total Solar Eclipse of 22 Dec. 1870", Proceedings of the Cambridge Philosophical Society: Mathematical and physical sciences, Volume 2, pp. 205-6:

     The instrument used was a refracting telescope by Dollond. . . . The cap containing the diaphragm was furnished with a touch-mark consisting of a projecting spoke. When in adjustment as described above this mark was parallel to the short side of the parallelogram.

   • 1880, "Survey of the Albemarle and Chesapeake Canal", Report of the Chief of Engineers U.S. Army, p. 864:

     The initial touch-mark was established at Roper's saw-mill, on the North River, and is a point on 20-penny nail driven flush with the horizontal surface of sill to bull-wheel.

References

1. ↑ Oxford English Dictionary, 2nd ed., 1989.