waywisers

Noun

waywiser (plural waywisers)

1. An instrument for measuring distance travelled, such as an odometer, pedometer, perambulator, etc.
   • I went to see Colonel Blount, who showed me the application of the "Waywiser" to a coach, exactly measuring the miles and showing them by an index as we went along.1656, John Evelyn, Diary
2. An instrument for determining direction (and possibly other aspects of one's travel as well).
   • Not being accustomed to this cruciform movement, I was not able, by the waywiser, to determine the real direction of the balloon, and on this account M. Robertson suffered to escape a considerable quantity of gas; on which we again fell till the barometer stood at 29 inches, about 50 minutes past...1832, Thomas Forster, Annals of Some Remarkable Aërial and Alpine Voyages
3. (figuratively) A guide; A means of determining the direction in which to proceed.
   • We have not sought to make a treatise, but only to set up a waywiser or signpost to show the road the law is taking .1931, Justice of the Peace and Local Government Review, page 461