This is a very nice looking watch ! 
 
The watch is Hallmarked 1916 London, the case was made by Borgel.
 
 Francois Borgel was a master watch casemaker who was one of the first if not the first innovator of water resistant technology in wrist watches, pre dating Rolex he patented in Switzerland in 1891 a movement which was screwed-in through the front of a one part case and then sealed off with a tightly fitting bezel and crystal, this mechanism also meant the movement was also dust proof another important innovation for the time. During World War One, Borgel,supplied cases ( mainly pocket watches it has to be said, but also wrist watches) to brands like IWC and Longines amongst many others. His recognisable Hallmark is a Key with the initials F.B. above it, this can be seen in one of the pictures. 
 
The Sterling Silver case has a couple of small dent on one side of the case otherwise in very good condition. The dial is also in very good condition for its age, Inside the case is a 15 Jewel Swiss Movement. 
 
Cosmetically overall this is in very good condition and is running well.