The Mercury was made in USA from cast aluminium and not finished in any way, they are consequently prone to oxidation - particularly if they have ever been anywhere near the sea. The beginning of this process can be seen on this example, along with blistering under the 'leather' covering. This is a very distinctive and handsome camera, although I've seen it described as "odd". The housing on the top of the camera is for the rotary shutter blades, the shutter speed being altered by changing the gap between the two blades - it is not simply a disc with a hole in it. Speeds of 1000th sec are possible. The camera is half frame 35mm, dictated by the rotary shutter, the camera would otherwise have been too large. It does, however, give a very useful 65 frames out of one roll of 35mm film and the shutter is extremely smooth. Acquired in California, November 2000, in deteriorating but generally sound condition.