In 1916 King Alfonso XIII of Spain bestowed the Echegaray Medal upon him; in 1918, he declined the offer of the position of Minister of Development. In 1920, he entered the Royal Spanish Academy, in the seat that had been occupied by Benito Pérez Galdós, and became a member of the department of Mechanics of the Paris Academy of Science. In 1922 the Sorbonne named him an Honorary Doctor and, in 1927, he was named one of the twelve associated members of the Academy. From 1922 to 1926, he participates to the works of the International Committee on Intellectual Cooperation of the League of Nations.