This paper discusses the application of the punched card equipment, now commonly used in statistical and actuarial work, to the analysis of complex spectra into terms. The spectral frequencies are punched on one set of cards and as complements on another. These cards are then passed in pairs through the tabulator which is provided with a summary punch. The cards from the summary punch are sorted and tabulated. The common differences as well as a code number indicating the lines giving rise to these common differences may be easily read from the tabulation sheet. With the aid of certain refinements, the method becomes very rapid and requires only routine attention on the part of the operator
