From Pocketwatcher.org
http://www.pocketwatcher.org/categor...eltclipchains/
How to wear your watch / belt clip chains
How to Wear your Belt Clip Chain
These chains made their appearance mostly in the Edwardian period up to the Art Deco period in the 1930's. Usually handsomely engraved with pinstriping or geometric designs and perhaps initials, these metal pieces slid over a belt with a chain attached with a swivel to hold your watch. The watch would then be placed in the trouser pocket, thus insuring safe keeping.