How does it work ?

This 19th-century instrument measures the area of any drawn shape. By tracing the perimeter, the device uses a trailing hatchet principle (tangent wheel) to approximate the total surface (Non-Holonomic Movement+Green’s Theroem).  It was used to calculate areas under mathematical curves, determine country borders, and analyze engine diagrams to improve machine efficiency.

How to build ?

The PDF instructions can be downloaded for free on this shop which includes the bill of material, the custom dial to print as well as the measuring sheet used in the video (to be printed on A4 size, 100% scale). If you want to go deeper in the mathematics explanations, you can read the article on the blog with is a transcript of the video with additional links.

About this product

Instructions preview