THE reasoning applied in the solution of a large number of physical problems involves the use, often unconsciously, of the principles of the Fourier transform. A pictorial solution in which the primary
dimensions may be simply computed, together with an appreciation of how the finer details are likely to modify the result, is often all that is required in the initial stages of an investigation. The rigorous solution may follow and may often be expressed entirely in mathematical form with complete precision but without necessarily indicating the form of solution or the behaviour of the system to the reader or student whose approach is not that of the mathematician. It is the aim of this book to make available to the experimentalist a guide to the principles and practical uses of the Fourier transformation. It is hoped that it will help to bridge the gap between the more abstract account of a purely mathematical approach and the rule of thumb calculation and intuition of the practical worker. The monograph springs from a lecture course which I have given in recent years and for which I have drawn upon a number of sources. In particular I was most fortunate to acquire in 1951 a set of notes compiled by the late Dr. 1. C. Browne from a series of lectures given by Mr. J.A.Ratcliffe of the Cavendish Laboratory. I most gratefully acknowledge my debt to Mr. Ratcliffe for this valuable introduction to the subject. I am indebted to Dr. H.J.J.Braddick, at whose instigation the book was compiled, and to many friends and colleagues for their ,helpful discussions and assistance.
R.C.JENNISON