Therefore, when it was laid down 40 times the actual distance,
according to your retracement, is only 39.80 chains. The factor
times record distance equals the distance needed to establish the
corner or the search area.

The proportionate methods used in resurveying the rectangular system
indicate the length of the chain used in the original survey. If
these factors are recorded, you will have a basis of determining
the index correction for the distance. A large or unusual variation
of this factor may indicate a blunder in the original survey, or
your retracement.

The term index correction as applied to linear distance is synonymous
with ratio and scale factor.