Railway surveys and construction, West Virginia, 1899-1900. Engineering design and construction, Pennsylvania, 1900. Assistant to chief sanitary officer at Havana, 1901-1902 inaugurating first successful campaign in the Western Hemisphere against yellow fever and malaria.
Research engineer mine plant construction, West Virginia, 1903. Health officer Panama Canal Zone, 1904-1914, also of City of Panama, during yellow fever epidemic, 1905. Determined the flight range limits of malaria conveying mosquitoes, 1912, and devised traps for making disease bearing mosquitoes trap themselves.
Sanitary engineer malaria investigating div. United States.P.H.S., 1915, senior sanitary engineer, 1917-1931. In charge anti-malaria activities at 28 extra-cantonment zones, Army and Navy camps, 1917-1919, reducing malaria sick rate to one-half of one per cent of that of Southern camps in Spanish-American War.
Director yellow fever control Mexican Oil Field Area, 1923. Director American Red Cross malarial control activities, Mississippi River flood area, 1927. Consultant in malaria control to Tennessee Valley Authority since 1935.