In spite of our desire to concentrate our entire effort on the work in which we were engaged, and in spite of the fact that our needs were so modest, we were forced to recognize, toward 1900, that some increase in our income was indispensable. Pierre Curie had few illusions about his chances of obtaining an important chair in the University of Paris, which would, even though it meant no large salary, have sufficed for the small needs of our family, and enabled us to live without a supplementary revenue. Since he was neither a graduate of the Normal School nor of the Polytechnic, he lacked the support, often decisive, which these big schools give their pupils; and the posts to which he might justly have aspired, because of his achievements, were given to others, without anyone's even thinking of him as a possible candidate. At the beginning of 1898, he asked, without success, for the Chair of Physical Chemistry left vacant by the death of Salet, and this failure convinced him that he had no chance of advancement. He was appointed, however, in March, 1900, to the position of assistant professor (_répétiteur_) in the Polytechnic School, but he kept his post only six months. In the spring of 1900, there came an unexpected offer, that of the Chair of Physics in the University of Geneva. The doyen of that University made the invitation in the most cordial manner, and insisted that the University was ready to make an exceptional effort to secure a scientist of such high repute. The advantages of this position were that the salary was larger than the average one, that it carried the promise of the development of a Physics Laboratory adequate to our needs, and that an official position for me would be provided in this laboratory. Such a proposition merited a most careful consideration, so we made a visit to the University of Geneva, where our reception was the most encouraging possible. This was a grave decision for us to make. Geneva presented material advantages, and the opportunity of a life comparable in its tranquillity with that in the country. Pierre Curie was, therefore, tempted to accept, and it was only our immediate interest in our researches in radium that made him finally decide not to. He feared the interruption of our investigations which such a change must involve. At this moment the Chair of Physics in the physics, chemistry and natural history course at the Sorbonne, obligatory for students of medicine, and familiarly known as P.C.N., was vacant; he applied, and was appointed, due to the influence of Henri Poincaré, who was anxious to free him from the necessity of quitting France. At the same time I was given charge of the physics lectures in the Normal School for Girls at Sèvres.