The Gyro Applied by K.I.T. Richardson Bf-109 The red maximum airspeed pointer

The red maximum airspeed pointer index is set by accessing an adjustment screw

the aircraft was traveling at 820 km/h

The knob has a small spring-loaded button in its center

Liquidometer

likely when they were removed from the aircraft

The Gyro Applied by K.I.T. Richardson Bf-109 The red maximum airspeed pointerThe Gyro Applied book, published in 1954, covers the fundamentals of gyroscopes and their applications in aeronautics and military and marine applications. The gyroscope was key to successful instrument flight from the early 1900's, and was central to many aviation instruments and automatic pilot systems. The 384 page book is in good condition.