Its been awhile since I last posted this watch here on this forum. Maybe with some of the new guys now posting I can get some answers as to what exactly it is. I bought this watch at an estate sale of a former WWII USAAF navigator who went on to become a pilot after the war and served up to the Vietnam War. His family knew nothing about the watch. He collected many aeronautical item, so there is no proof that this watch was actually issued to him. It might have just been one he found and liked and decided to add to his collection. Going by the serial number, it is pre-WW II. I am wondering what the P might stand for, also the X. I did also get an early white dialed Elgin Type A-11 that has a P in the serial number as well. I have quite a collection of of the white dialed Elgins a-11s and the markings on it are different than the others. Maybe they were both prototypes, "P" for their respective types?



Here are the photos

Any idea what "Time Laboratory" was?

I find it quite interesting. When you push the button on the side does it stop the balance wheel from turning.

Buy the looks from the back of the case I would say the movement is not original to the case. Because it has an extra screw mark. With pendant up. It would be at 1

I do know there were metal canisters the US Army Air Force used to house navigational watches during flight like a 4992B. They were produced by the Geo. Adamson Co out of Tecumseh Michigan and another company named "Time Laboratory" maybe one in the same. I will see if I can produce a photo of one. All the examples I have owned were by Geo. Adamson. Maybe there is a connection there for your "Time Laboratory" question? Your watch probably has something to do with "The Adamson System" which was a time keeping system used by the military during this time???? Don't know much about it but have heard of it. Greg may be a better help with that.

I believe Michael is on the right track. There were at least two suppliers of Watch, Navigation, Type A-9, Master, Mean Solar Time (21 Jewel) in the late 1930s/early 1940s. One was Time Laboratory, Tecumseh, Michigan, and the second was Longines-Wittnauer Company Inc, New York City. I don’t know the connection between Time Laboratory and the Hamilton Watch Co.

These navigation watches were used by the Air Corp Training Detachment, Miami, Florida in 1940 onwards at America’s first navigation training program.
http://www.panamair.org/History/Lunn.htm