Sorted newest first.
The corkscrew began as a gun-cleaning tool. In 1681, someone realized a spiral designed to clear musket barrels also worked on wine bottle corks. What followed was 300 years of patents for a mechanically simple problem.
In 1916, British artillery officers were strapping pocket watches to leather wrist cuffs to coordinate fire. Within fifteen years, the pocket watch was obsolete.
The magnetic compass was a Chinese innovation of the 10th century, a European navigation tool by the 12th, and a global standard within two hundred years. Almost none of the people who carried it understood why it worked.
Whitcomb Judson demonstrated his fastener at the 1893 Chicago World's Fair. It jammed, rusted, and opened spontaneously. It took forty years to fix.
The first traffic signal exploded within a month of installation, injuring its operator. Then nothing — for 45 years. The three-phase light we rely on today took half a century of engineering and institutional failures to arrive.
In 1903, a woman from Birmingham, Alabama watched streetcar passengers step out to clear rain from the windows by hand, and concluded there was a better way. The automotive industry spent two decades telling her she was wrong.
In 1930, a Swiss physicist accidentally invented the sensing principle behind the modern smoke detector while trying to build a poison gas alarm. The device that reached American homes in 1969 ran on nuclear weapons fallout.
James Dewar invented the vacuum flask in 1892 and refused to patent it. That decision cost him everything and turned a German businessman into a household name.
On a Miami Beach in 1948, Norman Woodland drew concentric circles in the sand and extended Morse code into two dimensions. It took twenty-six years to scan a pack of Wrigley's gum.
Fire has been portable since the 1820s, but safe fire only arrived in 1844—when a Swedish chemist realized the insight was separating the phosphorus from the match head entirely. Most accounts skip this distinction.
Before 1839, you could not make a reliable rubber band. The material existed, but it melted in summer and cracked in winter. Charles Goodyear's vulcanization process changed the polymer — and made a new class of objects possible.
For most of human construction history, there was no reliable way to find horizontal. The spirit level solved this in 1661 and changed how everything gets built.