The first vacuum cleaner was patented by inventor Hubert Cecil Booth in 1901.
The first vacuum cleaner didn't suck dirt up — it just blew it away with compressed air. Upright vacuum cleaners with bags on a stick followed in 1907, the brainchild of William Henry Hoover.
#10 An old choir director of mine lived next door to one of the guys who developed the earliest patents for home microwave ovens. They were approved and being marketed by the 70s, but he wouldn't have one in his house until the 90s because they still leaked too much radiation of some sort.