Front, Back, Cuvette, Movement, Attachment slot, Second attachment slot, Case without
movement, Inner assembly, Case mark, Backside of
protective cuvette
Edward A. Marsh was the unofficial historian of Waltham and wrote a number of pamphlet size booklets on the history and development of the company. He was also the superintendent around the turn of the century and designed machinery that followed in the tradition of the highly automated machines of D. H. Church.
In looking through the Waltham serial number list, one finds references to the "Marsh watch" which appears in a number of runs. This watch is not well known but the reason is probably that it does not attract much notice rather than pure scarcity.
The Marsh watch is unique in that is inserted into the case from the back rather than from the front. The "watch" consists of the movement, a protective ring and a protective cover. This would not seem to be any big deal except that the watch uses a special latch arrangement to hold the movement in the protective ring rather than regular case screws. This allows the entire assembly to be substantially thinner.
The watch is designed to be mounted in a very light gold case with the protective cover providing the necessary case stiffness. The original article on the Marsh case and the patent document tell the story of why and how it was made.