Mechanical Paradox Orrery
James Ferguson (1710-1776), from a humble Scots upbringing, and with little formal education, rose to become one a leading educator and a prolific writer of scientific books. He was a leading inventor of teaching aids used to explain astronomical principles as known to science at the time.
This simple device illustrated the direct motion of the moon’s apogee and the retrograde motion of it’s nodes, using the clever concept of epicyclic gearing, in common use today in many mechanisms. Ferguson made many over the years. Quite crude, made of wood and printed paper, very few survive.
My fully animated SolidWorks™ CAD model was based on an illustration (top) in the fascinating book Geared to the Stars, by Henry C. King, but I chose to show it as it may have appeared if constructed by a clockmaker of the period.
I intend to publish scale drawings and instructions for educational use in the classroom, thus carrying on the legacy of James Ferguson.