20-odd years ago, later at night, in supermarkets a contractor would be sweeping the aisles using a sweeper-vac thing with a pertol engine powered by liquified petroleum gas. Nowadays an employee uses a battery-driven machine of the same size.

20-odd years ago, later at night, in supermarkets a contractor would be sweeping the aisles using a sweeper-vac thing with a pertol engine powered by liquified petroleum gas.
Nowadays an employee uses a battery-driven machine of the same size.