In this second section of Unit 1, we will learn exactly what proportionate
measurement is and how it can be applied to finding a lost corner.
Then we will dive into our first method, single proportionate measure.
Section 7-7 of the manual defines proportionate measurement as:
Measurement that gives equal relative weight to all parts of the
line. In its simplest form then proportionate measurement can be
demonstrated as shown. These are the distances recorded by the original
surveyor.

These are the measurements taken by a later surveyor in search
of the original corner. The later surveyor has set a temporary stake
at the record of 45.

But we know that the true distance, P, cannot be 45, if we are
to apply the four-chain difference over the total length of the
line as the manual and common sense would indicate.