Stopwatch, Type A-8, Navigation Watch for Parts or Repair 1944 "Jitterbug"
Here is an authentic WWII-era aircraft navigator's Watch, Navigation (Ground Speed) Stopwatch, Type A-8, made by Waltham. With a serial # prefix AC44, indicating manufacturing year of 1944. Type A-8 stopwatches were used in any WWII aircraft with a navigator, such as heavy (B-17, B-24, B-29) and medium bombers (B-25, B-26) and large transports (C-46, C-47, C-54). This is offered for parts or repair as the crown and winding stem are missing.
The outer ring of the dial counts up to 10 seconds and the inner dial located at the standard 12:00 position count up to 10 minutes of the 10-second revolutions. The A-8 was known as the ‘jitterbug’ because of the loud and fast ticking of the balance at 144,000 beats per hour.
According to C.G. Sweeting’s book "Combat Flying Equipment":
The Type A-8 was a navigation stopwatch designed for timing ground speed meters for determining the velocity of aircraft relative to the ground. One revolution of the Type A-8 hand was equivalent to ten seconds. The dial was white on early Wittnauer Type A-8 watches and black on Waltham watches produced from 1940 onwards. Elgin produced a Type A-8, 15 jewel, black dial stopwatch under military specification no. 27749. Waltham, the Federal Television Corp. and Aristo Import Co. manufactured Type A-8 stopwatches under military specification MIL-W-6510 (specification published in August 1951 and superseded No. 94-27749A published in July 1945). Under MIL-W-6510, continuous running movements were required to have not less than 15 jewels and the non-continuous movements were required to have not less than 9 jewels.