The bookwheel, another version of the rotating bookstand, is a device planned to allow one person to read or study a range of heavy books in one location with no difficulty. The books are rotated up and down much like a Ferris wheel (as different to a flat, revolving table surface). This machine was made-up by Italian military engineer Agostino Ramelli in 1588. To ensure that the books remained at a constant angle, Ramelli incorporated an epicyclic gearing arrangement, a complex device that had only formerly been used in astronomical clocks. Ramelli certainly understood that gravity could have worked now as efficiently (as it does with a Ferris wheel), however the gearing system allowable him to display his mathematical prowess.