Paper, Calculation of the velocity of the air moved by the newly-invented centrifugal bellows by J T [John Theophilus] Desaguliers Bellows are seven feet in diameter, and one foot thick within, which a man can keep in motion with very little labour at the rate of two revolutions in one second Also attached is: - part of a printed page with Desaguliers notes for improvements to machine - letter to Cromwell Mortimer, dated 29 March 1736, concerning George Agricola's hessian bellows - list of errata to article in 'Philosophical Transactions' no 437 Read to the Royal Society on 12 June 1735 1736