Rare Antique US Navy Inclinometer W. Rieker Philadelphia Pat 1919 which was made into an IBM award. The inclinometer itself has not been altered and can be removed from the plaque if so desired. Guaranteed old and original. Pictures show size and condition. Founded in 1917, Rieker Instrument Company Inc began manufacturing high quality inclinometers using hand blown glass tubing to exacting customer specifications. It’s earliest applications were used in the medical and aviation fields, providing accurate quality low cost solutions for measuring tilt and acceleration. In the early 1920’s, the US Government contracted Rieker to produce bubble style pitch and roll indicators for the fast emerging aircraft market. One of the most famous installations seen in 1920’s, was the use of a pair of Rieker glass tube instruments on the panel of the Ryan NYP The Spirit of St. In 1927 Charles Lindbergh chose the lightweight Rieker P-1057 Degree Inclinometer to give him climb and descent angle information. Rieker’s ability to produce precise instrumentation for the aviation industry led to our status as a dominant supplier to Original Aircraft Manufacturers to this day. Our specialty glass department still hand crafts replacement slip indicators for vintage aircraft around the world.