d. Engraved image done with surveying equiptment

An engraved image of what could be done with surveying equipment set up at two points on an improved piece of land. From each station any number of angles and distances could be measured, allowing for any possible use at the time of the survey or any time in the future. With each station point marked and preserved, additional calculations could supplement this work later. Applying triangulation and trigonometric calculations to the observations made here could extend this plan well to the opposite side of the stream (Source: Encyclopedia of Source Illustrations).