I have been a nurse since 1976. I think that one of the factors that motivated me to be a nurse is my favorite Aunt Rosie who was a nurse in WW II. I remember her having one of these watches which is worn as a pin and has a cord that allows you to extend the watch to see it straight on.
This is a fine Elgin example in Sterling Silver case with an Onyx pin. The serial number makes it 1939. It has 15 jewels and still runs!
The face of the watch is 1 1/8" in diameter and the diameter of the pin is 7/8". The watch and pin are 2 1/2" long but can be extended to almost 10". The clasp and the coil of the wire chain work great.
A piece of history.