Working model of a differential analyser constructed from the construction toy, Meccano, by Prof. Douglas Rayner Hartree and Arthur Porter at University of Manchester, England, 1934, and reconstructed by Prof. Douglas Rayner Hartree at University of Cambridge, England, 1947.
A differential analyser is an analogue computer designed to solve equations using a wheel and disk mechanism. This model was built using the toy Meccano over 18 months by research student Arthur Porter. Porter was working under the supervision of Professor Douglas Rayner Hartree (1897-1958), a professor of theoretical physics, who was waiting for a full-size analyser to be built. Although it needed setting and operating by hand, the machine was able to solve difficult equations.