Equate
Equate , transitive verb
[Latin aequatus, past participle of aequare to make level or equal, from aequus level, equal. See Equal.]
To make equal; to reduce to an average; to make such an allowance or correction in as will reduce to a common standard of comparison; to reduce to mean time or motion; as, to equate payments; to equate lines of railroad for grades or curves; equated distances.
Palgrave gives both scrolle and scrowe and equates both to F[rench] rolle.
Collocations (2)
Equating for grades (Railroad Engineering) , adding to the measured distance one mile for each twenty feet of ascent.
Equating for curves , adding half a mile for each 360 degrees of curvature.