So yesterday, I was at a thrift shop looking for some old books. This shop often sells really interesting old books, but as for watches, it is... well... not the right place to go to. But anyway. When -on my way to the books section- I passed the showcase for watches, I instantly noticed something of interest in there. The showcase never featured ANY interesting watches in the last 5 years as the thrift shop always forwards nicer watches to the jeweler. So i took a closer look at this thing. I had NO clue what it was and where you could use such a thing. I had to buy that one and I'm fully aware that I oberpaid, but I knew I wouldn't be able to sleep otherwise. Some pictures: Trigger on the left = stop Pushing the trigger some more to the left = resetting the minute hand (no impact to the small second). Somehow the movement also gets wound by being pushed to the left. Pushing the trigger to the right = movement runs. It only runs for twelve minutes, the movement stops automatically after one round. Now let's talk about the thing: Firstly, there is no hour hand. There is a small second with a base of 48 (what would you need that for?!) and a minute hand with a base of twelve minutes. The markers between the minutes indicate that 12 seconds have passed by. Again: why and how would such a base be useful? Google helped a bit. So I found out that this thing was used in the early telephone industry, this "Telephonometer" was developped in 1905. The two screws at about 5 & 7 were connected to a jack. On 3, 6, 9 & 12 minutes it triggered an electrical impulse in order to light a lightbulb near the telephone. So the caller new that his talking time was almost up - if he wanted to, he could continue the call so he had to pay for another three minutes. I've read some contradicting information about how and when the light was turned on though. The only questions remaining are: Why did they use such uncommon bases (48 for seconds, 12 for minutes and also 12 for between the minutes)? Thanks in advance!