Hatchet Planimeters

Our school was doing 3 day trip to Yosemite with the theme of "Restore Hetch Hetchy." Each discipline had to come up with a lesson that related to this theme and I decided to try to use a relatively unknown tool to estimate the volume of water stored by the O’Shaughnessy Dam: a planimeter. There are 3 types of planimeters that I researched: Linear, Polar, and Hatchet. I thought that a hatchet planimeter would be the easiest because as long as you could find a dead branch, a patch of dirt, and th