Inventions of the 20's include the radio, refrigerator,
the band-aid, the polygraph machine, the hair dryer (not the portable kind), the toaster, the vacuum cleaner, the washing
machine, the liquid fueled rocket, kool-aid, the internal combustion engine, q-tips, bread slice, the bulldozer and the traffic
light. Most of the inventions were used in everyday life, were others were used once in a while. The consumer
market was huge for these goods because the stock market boom. The invention of the assembly line also
helped mass produce these inventions at a lower cost so they were more affordable.