1" S of the specific heats of metals and alloys in the liquid helium range of temperatures are of fundamental importance in the field of solid state physics, In this temperature range the lattice specific heat usually follows the T a law, the electronic specific heat is proportional to the absolute temperature, and other contributions to the specific heat are comparatively small. The method of least squares is most useful in analysing a series of experimental results at different temperatures to find the individual contributions, but the evaluation and assessment of specific heats at a number of temperatures from the experimental observations in the liquid helium range of temperatures can be extremely laborious if the highest accuracy is required.
Shortly after the installation of a Pegasus digital computer in this University, programmes were developed which carried out most of the numerical analysis associated with helium and hydrogen range calorimetry, reducing the time of computation from about a week to a day. 1 During the development of these programmes it became obvious that no appreciable further reduction could be made in the time required for the analysis of results unless means were found for automatically recording the results in a form suitable for direct input into the computer. However, the possibility of building a recorder for the existing calorimeter (described by Hoare and Yates 2) seemed remote, since the experimental observations consisted of a mixture of bridge settings, potentiometer settings, and galvanometer readings taken at predetermined times. The cost of digitizing and recording all these quantities would have been prohibitive.
Fortunately, while the computer programmes were being developed it was decided to build a new apparatus for the measurement of specific heats at low temperature, making use of the bulk liquid helium which was at that time becoming available through the 'pool' scheme. It was realized that the construction of a new