A very rare chess timer manufactured by E. Buysse, South Bend, Indiana in the early 20th century.

So rare, in fact, that it's not a chess timer at all. Thanks to the research of David Delucia, this timer has been shown to be a pigeon timer!

Eventually I will remove this timer from my chess pages, but meanwhile it remains listed for the edification of anyone who runs across one of these interesting (but non-chess) devices.