After some comparative studies with other watch information available on the internet,
we are able to determine that the S.Smith&Son chronograph with the Imperial Japanese Navy
identifier #278 is a Ed. Heuer Ref 102 A.



This watch was most likely procured between 1921-1924. This watch has a serial number in the exact same range and is dedicated in 1924
Note: S.Smith&Son is a known supplier to the British Admiralty and also to the RAF.

This is from Konrad Knirim's books.
At this point, I can only speculate to the use of the watch at that time period. So the Imperial Japanese Navy and the British Royal Flying Corp were heavily involved in an exchange of technology in
order to strengthen Japan's naval aviation capabilities. Since these planes were now capable of longer distances and required navigation over water, it may have been an experiment to see if chronographs
could help either time bombs or help navigation to find the newly developed aircraft carriers. As we know, distance and fuel was very difficult to calculate so the amount to time maybe the only alternative
to determine how much fuel is left.


sky soldier
空兵
Sempill Mission