Resumen de George Graham and the Orrery
In his 1734 discourse on the planetarium, John Theophilus Desaguliers was careful to point out that the invention of the orrery had been incorrectly attributed to John Rowley and that it was George Graham who had made the first truthful working model of the Earth and Moon’s motion around the Sun. Two such models by Graham survive in Museum collections: one at the Adler Planetarium in Chicago and the other at the History of Science Museum in Oxford, UK. This paper assesses the differences between the two instruments and the physical evidence contained within to test out the unfounded assertion made by Henry C. King that the Adler instrument is the prototype and the Oxford orrery a developed commercial product.
