To the right in this image is an example of a Swiss Burna brand, Type 89 Gun Camera Chronograph. For comparison, it is next to an approximately 16 size Seiko (Seikosha) Navy issue chronograph.

Until some recent postings on the Japanese Military Timepieces Forum, the use and purpose of the Type 89 was something of a puzzle. As it turns out, the Imperial Navy Type 89 shooting practice camera (also called a intervalometer? ) was a training devise. This item closely resembles a Japanese issued Lewis aircraft machine gun. While I have seen an image of the gun camera, I do not know exactly how it worked, other than the obvious fact that it must have been used to train airmen to effectively use the Lewis machine gun.

Translation of the information on the back of the Burna was furnished by Naoki (Student3). Liga also provided information about the gun camera.

From the top, "Air Soldier",
next line, "Type 89",
third line down, "Activity photo gun/ equipment option 2" the last line is the serial number.

Seiko also made Type 89 chronographs. Unlike the regular chronographs Type 89 Seiko's had black dials, like the Berna. The markings on the back of Seiko Type 89's are the same.

Naoki also shared information obtained from a surviving Japanese pilot, who stated that tword the end of the war, chronographs were removed from training devises and re-issued as regular pilot's watches. The veteran pilot also stated that the imported Swiss Berna's were the most highly regarded by Japanese pilots at that time.

Best regards,
Greg

JAPANESE MILITARY WATCH FORUM

Additional research regarding the Type 89 can be found in the Japanese Military Watch Forum, noted above.

Best regards,
Greg

Thanks to Rich over on the Japanese Military Watch Site, we now have some images of the Type 89 Gun-Camera which depict the mounting of the Type 89 chronograph.

Best regards,
Greg

Here we have a WWII or pre-WWII period image salvaged from film found in a Type 89 Shooting Practice Camera.

The face of the chronograph can be seen as the student "shoots" at an attacking aircraft. The chrono dial appears to have some extra markings I have not seen before.