R.D. Martin, AE1, points out the electrical circuit in the heating system of the P2V aircraft. Stamped on the back is "U.S. NAVAL AIR STATION BRUNSWICK, MAINE" and "OFFICIAL U.S. NAVY PHOTOGRAPH NOT FOR PUBLICATION UNLESS OFFICIALLY RELEASED" and "RELEASED IF PUBLISHED CREDIT MUST BE GIVEN AS FOLLOWS 'OFFICIAL PHOTOGRAPH U.S. NAVY'." Undated
