As a preliminary step in the investigation of the problem of detecting a non-metallic body buried in soil at a shallow depth,
a critical study was made of the various ways in which such a body might vary physically from its surroundings. One way in
which such a body might differ from the enclosing soil was in such thermal properties as heat conductivity and heat capacity.
The possibility of turning such differences to account in the problem of detection, however, seemed a very remote one. As
it was desirable that no possibility, however remote, should be ignored it was decided to make a brief investigation of the
thermal properties of soil and non-metallic materials such as might be used in the construction of the body in question. The
following notes give the salient features of this investigation and show that detection of the buried object by virtue of
its difference in thermal properties from the soil cannot be considered feasible. As a working hypothesis, it was assumed
that the processes of heat exchange in the cycle of solar energy absorption and re-radiation would be changed in the vicinity
of the buried object. The notes, therefore, deal briefly with this cycle, and the factors which influence the amount of solar
energy absorbed and re-radiated.