This waywiser has a wooden frame, and a dial of silvered brass with the usual scales, one
for poles and furlongs, and the other for miles. There is also a small inset dial that is divided into
100 sections, the use of which is unknown. Thomas Heath and Tycho Wing worked together in
London during the period 1751-1773.
Ref: Gloria Clifton, Directory of British Scientific Instrument Makers 1550-1851 (London,
1995), p. 131.