The Collaborative International Dictionary of English v.0.48:

Gunter's scale \Gun"ter's scale`\
   A scale invented by the Rev. Edmund Gunter (1581-1626), a
   professor of astronomy at Gresham College, London, who
   invented also Gunter's chain, and Gunter's quadrant.
   [1913 Webster]

   Note: Gunter's scale is a wooden rule, two feet long, on one
         side of which are marked scales of equal parts, of
         chords, sines, tangents, rhombs, etc., and on the other
         side scales of logarithms of these various parts, by
         means of which many problems in surveying and
         navigation may be solved, mechanically, by the aid of
         dividers alone.
         [1913 Webster]