在两份信封的背面,写有达格准将H.A. 达格亲笔的以下文字: “I certify that this letter was carried by the U.S. Army Pan American flight over 20.000 miles through Mexico, many nations of Central and South America and back to Washington D.C. via the West Indies, Dec 21, 1926 to May 2, 1927 “
在两份信封的背面,写有达格准将H.A. 达格亲笔的以下文字: “I certify that this letter was carried by the U.S. Army Pan American flight over 20.000 miles through Mexico, many nations of Central and South America and back to Washington D.C. via the West Indies, Dec 21, 1926 to May 2, 1927 “