Today in the history of astronomy, an astronomer with a talent for mechanical design is born. | Published: April 25, 2026 The frontpiece of Astronomy Explained upon Sir Isaac Newton's Principles displays an illustration of an orrey that James Ferguson built. Credit: Linda Hall Library Born April 25, 1710, to farmers in Scotland, James Ferguson only had three months of formal education. Despite working as a shepherd, he taught himself mechanics and astronomy, using his evenings to map the skies with beads and string. He went on to become a repairer of clocks, and applied those mechanical skills to his interest in astronomy, building a machine with rotating plates that could predict eclipses and map the movement of the Sun and Moon (the “Astronomical Rotula”). He also designed and built multiple orries – according to stories, understanding the complex gearing with remarkably little study.  Ferguson relocated to London in 1743 and began giving lectures on astronomy and mechanics.…