Natural graph created by the sun, a magnifying glass, and a tree.

Someone on Reddit posted this cool picture of a...contraption? I'll go with contraption. Anyway, it automatically generates a chart of the amount of sunlight per day by burning a log. A Twitter follower recognized this as a Campbell-Stokes recorder.

This is beautiful art and data visualization from Hood-Glen Park in San Francisco.

How to use in class:
1) Make a bunch of really dumb logarithm jokes.
2) A nice introduction to data visualization. Maybe this could be paired with more traditional sources of weather data.
3) Also makes me think of other naturally occurring charts:

Also, while less pretty, think about all the data that is automatically created every time Google Maps identifies your location (and then warns everyone using Google Maps to avoid traffic slowdowns) or Netflix provides you with recommendations based on viewing habits. The Campbell-Stokes recorder could serve as a metaphorical segue into a discussion about all the automated data collection that goes on around us at all times.