frozen food (1924)
intelligence testing (1905)
automatic rifle (1918)
World Wide Web (1989)
transistor (1947)
aqualung (1943)
Scotch tape (1929)
moving assembly line (1913)
television (first all-electric image) (1927)
razor (1901)
liquid-fueled rocket (1926)
permanent artificial heart (1982)
fiber optics (1955)
cyclotron (1931)
single-rotor helicopter (1939)
polio vaccine (1952)
military tank (1914)
e-mail (1972)
airship (rigid) (1900)
electron microscope (1932-9)