"The cooling by conduction of an intrusive sheet in the neighborhood of a contact is discussed, taking into account the effect of heat of solidification. General formulae are given, and the important case in which the magma and country rock have the same thermal conductivity and density and the magma is intruded at its liquidus temperature is discussed in detail. Numerical values for the contact temperature are given for this case, calculated for various values of the range of solidification and latent heat of the magma. These values are more than 100 degrees C higher than those calculated by previous workers who have not adequately allowed for the effect of heat of solidification."