The relationship between electric potential and temperature in a current constriction which is symmetric with respect to the contact surface; that is, the φ-ϑ relation

We shall find: 1. that in a current constriction, which is symmetric with respect to the contact surface, the R I 2 heat, that is generated by the current in the constriction, flows along the same path as the electric current; 2. that this fact is the foundation stone for the φ-ϑ-relation, where φ is the electric potential in a point of the contact constriction and ϑ is the supertemperature in the same point, measured from the temperature of the bulk of the contact members.