Pascal's contributions to physics might appear limited: his research was confined to the investigation of the vacuum and the statics of fluids, and only a few relatively brief publications resulted. These include the Expériences nouvelles touchant le vide (1647), Récit de la grande expérience de l'équilibre des liqueurs (1648), and Traités de l'équilibre des liqueurs et de la pesanteur de la masse de l'air, which were published posthumously in 1664. However, these works are still admired for their rigour and held up as models of empirical investigation. Pascal's experiments were carefully designed to converge on the causes of phenomena. In his posthumous works especially, equally important to the design of his experiments was the manner in which he presented them to his readers, placing them in an order which, with his accompanying analysis, extended a few simple principles to a wide variety of phenomena and produced an illuminating synthesis of existing knowledge.