by World Power Conference (Sectional: Water-power)

1927

by World Power Conference. Sectional Meeting

1927

by Boston World peace foundation

1923

by World peace foundation, Boston

1923

by World Peace Foundation

1926

by World Power Conference

1930

by World Peace Foundation

1923

by World Power Conference. American Committee

1935

by World Power Conference. International Executive Council

1929

by World Power Conference. American Committee

1925