This model was made by the Parisian instrument maker Robert Henri to illustrate the causes of lunar and solar eclipses. This view shows the Earth-Moon globes next to the Zodiac Ring and the bras Sun orb. Mounted on the bras ring, the Moon globe will rotate through string and pulleys as the wood and metal framework is turned. As the Moon globe croses the zodiacal ring, showing the Sun's path in the sky, an eclipse will occur if all three bodies lie in a straight line. The model is from a now incomplete set that was purchased for the Science Museum by Colonel Scott at the 1867 World Exposition in Paris, France.
© Science Museum / Science & Society Picture Library