A twin Bofors 40mm anti-aircraft gun used by the US Navy in World War 2, photographed at the Mining and Historical Museum in Galena, Kansas, USA, which is housed in the old Missouri-Kansas-Texas Katy train depot on historic Route 66. The ribbed section on the twin gun barrels is a water jacket for cooling; the two outlying structures below this are the gun sights. Also visible are the pointer's seat and handwheel at right, trainer's handwheel at left and drive motors at lower left and right. The gun was designed by the Swedish firm Bofors AB in the 1930s.