For the first time in the history of the physics department, an external examiner was called in to judge the significance of my work. Remember, before I arrived at U. of T., physics in Canada began and stopped at the doors of the McLennan Laboratory. To my surprise, and the astonishment of the prig mentioned earlier, the examiner gave his approval. That meant that all that remained to be done was to defend the dissertation before an assembly of physicists from the department. A second defence, termed a senate defence, would be more or less ceremonial and would be open to a wider audience.