Other
Airplanes
2
Airports
2
Bridges
2
Hangars
2
Night
2
African Americans
1
Air mail service
1
Air pilots
1
Aquatic sports
1
Canals
1
Cancer
1
Centennial celebrations
1
Construction industry
1
Defense industry
1
Domestic life
1
Dredging
1
Electric signs
1
Explosives
1
Fireboats
1
Floods
1
Helicopters
1
Hospitals
1
Housing
1
Infants
1
Lifesaving
1
Medical aspects
1
Medical care
1
Medical education
1
Medical equipment & supplies
1
Motion picture theaters
1
Nursing
1
Operating rooms
1
Petroleum industry
1
Photography
1
Poliomyelitis
1
Radiography
1
Railroad stations
1
Rowing
1
Sick children
1
Suicide victims
1
Surgery
1
Urban growth
1
Water pollution
1
Women's hospitals
1
World War, 1914-1918
1
Wrecking
1