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Made with an XP drawing tablet connected to a PC, drawing in Photos.
Image source:
George Arents Collection, The New York Public Library. “Flying-Fish.” The New York Public Library Digital Collections. http://digitalcollections.nypl.org/items/510d47da-91f3-a3d9-e040-e00a18064a99
When I first got interested in measuring the heights of trees, after reading a wonderful book called The Wild Trees: A Story of Passion and Daring by Richard Preston, I thought that finding the tangent was the best way to calculate the height of a tree. After all, I didn’t have a way to measure the hypotenuse — the distance from me to the top of the crown. However, a laser rangefinder let’s you calculate that distance, which in turn makes it much easier to get an accurate reading for the height of a tree. Thanks to the Eastern Native Tree Society (ENTS) for posting a helpful article about this.
Here’s a link to the article.
And a file download: