Airspeed Indicator (for the Patin "Dreiachsensteuerung"), 450 km/hr, Luftwaffe

This is an authentic WWII-era Airspeed Indicator as used in aircraft of the German Luftwaffe. This is an unusual instrument in that it has a knob which rotates a pointer (sitting at 190 km/hr in photo) along the scale. 

According to a very knowledgeable colleague:

"It is indeed the speed indicator for the Patin "Dreiachsensteuerung", a 3 axis autopilot developed at the start of the war. Rather than control the pitch of the aircraft directly, the autopilot controls the speed of the aircraft. The speed of the aircraft will depend on the throttle setting and on the pitch of the aircraft. If the aircraft flies slower than the set value on the instrument, the autopilot will pitch the aircraft down until the speed matches the set value. So if the pilot wants to maintain level flight, he needs to balance the throttle setting with the speed setting of the instrument. He can now regulate the climb rate purely with the throttle while maintaining a constant airspeed. The instrument contains a second winding that regulates the roll angle in relations to the speed. In this way the autopilot can automatically fly curves with zero slip."

The dial is in good condition given its age. The paint, less so. The knob turns the small pointer cleanly.