Example of American Flag Cancellation from Balboa, California
This is an example of the impression made by an American flag cancelling machine. This particular item is from an envelope cancelled in 1935 at Balboa Island, California. This is a late usage of the machine type, as most were gone by the 1930's.
As described in my machine cancel pages, the American company manufactured a large number of machines that impressed the flag cancellation. Collectors find these markings on postal items from the late 19th through first third of the 20th centuries.
More information about machine cancels can be found at The Machine Cancel Society web pages.