Account of different instruments presented to the Royal Society by John Theophilus Desaguliers Different instruments were: a) machine for making the different forces and velocities of a body moving in an ellipse around another body b) pyrometer c) two sorts of diving bells and models in glass of all Halley's instruments for that purpose d) model of Desaguliers's planetarium e) model of a wheel to exchange bad air for clean air October 1733 to October 1734