Tech of the past: Stationary Steam Engine
The steam engines in this picture were used to power large factories. Engines like these were incredibly stable and accurate when it comes to speed, so they were very useful for precision tasks. They were also very efficient, which saved the factories money in the long run. These engines were built between the 1850s and 1880s and were used for decades.
Photo by Wally Bahny for TechRepublic