OC109.)BOXED WWII JAPANESE PHONOTELEMETER: in a superb state of preservation. Functions perfectly. Ask for a video showing this photometer actually working and you'll agree that it's smooth. 50mm wide (2") and looking very much like a stop watch (which it is of course). This is a phonotelemeter, an instrument that measures the time and distance between the flash from a naval gun or an artillery piece and the actual report. Measures the time in seconds and minutes as well as the distance in meters. Note the clean sweeping black hand with needle as well as the smaller needle near the top which measures the minutes. The inside dial around the entire circumference measures the time in seconds. Like a stopwatch this instrument is activated by pressing down the start/stop button at top. Beautiful, clean white dial with crisp, intact numbers. Marked to Japanese maker 'SEIKOSHA' and 'PHONOTELEMETER'. I haven't opened the back of this time piece and don't want to gouge and force the lid. But believe me, it functions perfectly. Comes in 3x5 hinged wooden case with black printed Japanese characters on the lid. Interior is lined with plush purple velvet and is recessed to snugly accommodate timepiece. Note the link below which shows an identical cased example auctioned way back in 2017 for $500.00. EXC++++

I ran this time piece on four different occasions for over four hours each and it kept good time. 

https://www.willishenryauctions.com/catalogs/military-timepieces-collection-auction-march-18-2017/lot-41-seikosha-phonotelemeter/