They have a reconstruction of a device that was used to sort by size the oranges that were grown there. Below are a couple of pictures. As you can likely see, the oranges are dumped in at the upper end. As they roll down the inclined top they fall into the gap between the boards that form the top. However, since the boards are closer together near the top of the "hill", and farther apart toward the bottom, the oranges fall through into the various crates based on size.
Jane Glennan is the Outreach Coordinator at Historic Spanish Point. She asked me if I would make a model of the orange sorter that she could use when she goes out and makes presentations on Historic Spanish Point to schools and other groups. Here is my miniature version. It is about 15 inches long, and is designed to sort three different sizes of wooden balls.
Below is the completed model. Jane supplied the little crates and decorated the wooden balls as faux oranges.