1989

This propulsion wind tunnel (PWT) at Arnold AFB was the first large-scale facility for testing jet and rocket engines in simulated high-speed flight conditions. It has a unique combination of transonic (1955) and supersonic (1960) wind tunnels using a common 236,000 horsepower drive, the world's largest when built. It can achieve air speeds up to Mach 4.75 at altitudes up to 150,000 feet in its 16-foot square, removable test sections. Design engineers were Lief J. Sverdrup, John R. Parcel, Brice Smith, and Walter Cook, of Sverdrup and Parcel, St.

Ancient Chinese literature refers to the Zhaozhou Bridge as a "crescent moon rising from the clouds" or a "rainbow in the sky."  Throughout its history, it has been known as the Anchi or Anji Bridge (literally "safe crossing"), the Dashi Bridge ("big stone"), and the Dashiqiao ("great stone") Bridge.

This collection recognizes the inventive talents of John Moses Browning (1855-1926), a prolific and significant designer of sporting and military firearms, whose designs were known for simplicity, accuracy, and reliability. He held more than 128 patents covering 80 distinct firearms produced by Winchester, Remington, Colt, Fabrique Nationale, Savage, and General Motors (during wartime), among others.

Published in 1914-15, the ASME Boiler and Pressure Vessel Code (BPVC) was the first comprehensive standard for the design, construction, inspection, and testing of boilers and pressure vessels. With adoption in the United States and use in many countries, it has contributed significantly to public safety and influenced the continued development of boiler and pressure vessel technology.