Note: The Jerry Wahl Refernce Article on Double Proportion is an
excellent resource. This article can be accessed from the resources
In this part of Unit 2, you should become familiar with the specific
techniques of double proportionate measure, where it should be applied,
and how computations are done.
In this section on double proportionate measure, we will apply
the things you have already mastered in Unit 1 on single proportionate
measure, and extend them to encompass another common field problem.
One where four corners or more are identified, and these are located
in all four cardinal directions from a lost corner.
For this reason, double proportionate measure is often referred
to as four-way proportion. This method of corner restoration is
generally applicable to the restoration of a lost corner common
to four townships . . .