important Longines Wittnauer reference 4356 in stainless steel pilot's wristwatch with sweep centre seconds and Weems Second Setting System Model: Weems Material: stainless steel Reference N°: 4356 Year: 1947 Case N°: 21123-15 Caliber: 37.9 Movement N°: 5942315 Bracelet: leather strap Dimensions: 47mm Lieutenant Philip Van Horn Weems was a U.S. Navy commander born in Tennessee in 1889 and during his career serving his country at sea, he was the inventor of several navigational innovations. One of its best-known inventions is the Second Setting System, designed to help aviators plot their courses more accurately. Thanks to him it can be said that a new kind of watchmaking was born: Weems deducted that the difficulty in setting the watch came from the fact that, at the time, it was almost impossible to set the second hand exactly. The present model features Weems’ second setting system, with an inner rotating dial to improve accuracy in timing and synchronicity, vital for aviation and on seafaring expeditions which was subsequently patented by Longines in 1935.