The Arc and the Rivet
The development of reliable arc welding 👨🏭 technology is an advance that most of us don't dwell on, but it transformed engineering.
Prior to effective arc welding, most large steel structures - from bridges to ships to the Eiffel Tower - were riveted together. But welds are generally stronger, faster, and quieter to make. Woe unto you if you lived next to significant construction in the '20s or the '30s. The enormous hammering sound generated by pneumatic rivet guns was a hallmark of working with steel at the time.
The iconic image of "Rosie the Riveter" came, somewhat ironically, after the heyday of the rivet. "Rosie" worked with aircraft aluminum, however, and metals like aluminum (that are not amenable to welding) continue to use rivets to this day.
Just look at the shell a jetliner the next time you board a flight. The rivets are smooth and flat, but there they are.