by National Safety Council

1921

by National Municipal League

1905

by National Municipal League

1909

by National Electric Light Association

1930

by National Electric Light Association. Convention

1930

by National Electric Light Association. Convention

1886

by National Electric Light Association

1919

by National Electric Light Association

1914

by National Electric Light Association. Convention

1928

by National Electric Light Association

1896

by National Fire Protection Association

1916

by United States. National Bureau of Standards

1932