
Pocket watches did not always wind and set at the pendant (winding crown or stem). A lot of people are surprised to learn that a key was used at one time. There were many types of keys from fancy ones to advertising ones and the wealthy sported gold ones. There were also ratchet type keys to make winding easier. Key sizes varied since they had to fit the different size arbors on the watch. They were usually around a inch and a half in length and were attached to the pocket watch chain or chatelaine.
Here is some additional information from Wikipedia:
The very first pocket watches, since their creation in the 16th century, up until the third quarter of the 19th century, had key-wind and key-set movements. A watch key was necessary to wind the watch and to set the time. This was usually done by opening the case back and putting the key over the winding-arbor (which was set over the watch’s winding-wheel, to wind the mainspring) or by putting the key onto the setting-arbor, which was connected with the minute-wheel and turned the hands. Some watches of this period had the setting-arbor at the front of the watch, so that removing the crystal and bezel was necessary to set the time.