Plate, diagram of motion of three mutually attracting bodies by William Fishburn Donkin Diagram illustrating the motion of three mutually attracting bodies. Subject: Mathematics Published in Philosophical Transactions as 'On a class of differential equations, including those which occur in dynamical problems. - Part II'. Written by Donkin in Oxford. Received by the Royal Society on 17 February 1855. Read 22 March 1855. 15 February 1855