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.