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In 1934, Dr. Sawyer made another trip to Brazil to inspect yellow fever control activities, including an investigation of a puzzling outbreak of the disease in a rural region. In a welcome contrast to earlier visits to South America, Sawyer was able to travel by plane to more remote areas, rather than by water or on horseback. Sawyer called this aircraft the "flying cow" in the caption on the back of the photograph.. NOTE: The original photograph is very light.