A Machine for the Rapid Summation of Fourier Series

A machine is described which is capable of performing automatically the process of Fourier synthesis by the methods used in X-ray crystallography by Beevers and Lipson, the Fourier terms being added in at the rate of about one every 2 sec. Except for the counters, which can be obtained at moderate cost, the entire machine is built from standard telephone and radio accessories, and its low price and simplicity of construction make it practicable for it to be acquired by individual crystallographic laboratories. The machine has been built and tested with experimental counters.