20. inventor product inspired by
children sending
signals to each other
Dr. Rene Laennec Stethoscope by tapping on either
end of logs
spokes of a ships
Samuel Colt Six-shooter revolver
wheel
John Dunlop Rubber tires garden hose
seeing water
James Carrier Air conditioner condense on the side
of a glass
movements of a
Thomas Edison telegraph
water pump
spray-injection his wife spraying
Charles Duryea carburetor herself with perfume
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