VERY FINE EXAMPLE OF THE THATCHER FERRY BRIDGE ERROR. ONLY ONE PANE OF 50 WAS EVER ISSUED.
According to Canal Zone Stamps, one sheet, consisting of four panes of 50, was printed. Three panes were caught by postal authorities, while the fourth pane of 50 was sent to H. E. Harris & Co. as part of a larger order from the Canal Zone Philatelic Agency. At the same time this error was printed, the U.S. had issued the Dag Hammarskjold error in huge quantities. The Canal Zone authorities made plans to do the same, but were successfully sued by H. E. Harris, and the larger printing never took place. Two of the three other panes were laminated and presented to the National Postal Museum. The third was destroyed. The one pane available was broken up in 1969.