Leatherbound presentation copy of Introduction à la Théorie de la Relativité: Calcul Différentiel Absolu et Géométrie (Introduction to the Theory of Relativity: Absolute Differential Calculus and Geometry) by Henri Galbrun - Docteur ès sciences. Actuaire de la Banque de Paris et des Pays-Bas (Doctor of Science. Actuary of the Bank of Paris and the Netherlands) and published by Gauthier-Villars et Cie Editeurs; Paris in 1923. Signed and inscribed by Henri Galbrun to Horace Finaly - Directeur Général de la Banque de Paris et des Pays-Bas (Managing Director of the Bank of Paris and the Netherlands (Paribas) between 1919 and 1937). French text. Unique presentation copy. Fine binding. The book is in very good condition (gilt decorated brown leatherbound boards with gilt lettering to banded leather spine) with light rubbing to corners and spine edges. The hinge of the front board is just beginning to crack at the top but is still very firmly in place. Gilt top page edges. Marble endpapers. Internally the pages are clean and tight and there are no tears or other inscriptions. Henri Galbrun was a French mathematician known for his work in actuarial science, specifically the mathematical theory of insurance (life, disability, and sickness insurance), and for his contributions to the field of fluid dynamics through the derivation of what is now known as Galbrun's equation. A graduate of the École Normale Supérieure in the class of 1900, and having earned his agrégation in mathematics in 1903, Henri Galbrun passed the competitive examination in 1906 for the position of commissioner-controller of life insurance companies, a body of civil servants created in 1898 to ensure the solvency of the rapidly expanding insurance companies. He resigned from this position in 1909 to devote himself to mathematical research. After defending his doctoral thesis in 1912 and participating in the First World War, where he was assigned to sound-ranging operations like many other graduates of the École Normale Supérieure, he was appointed lecturer at the Sorbonne and then in Marseille. He left Marseille on October 1, 1922, to become a consulting actuary at the Banque de Paris et des Pays-Bas, a major investment bank founded in 1872. Horace Finaly (1871-1945) had been its general manager since 1919, a position he held until his death. 457 pages ISBN: N/A The book will be packaged in an industry standard mailer and shipped using a trackable service. IMPORTANT: Customs fees and VAT are included in the shipping cost for all EU countries. Delivery to the EU will be handled by DHL.