Heyday of the Stirling Hot Air Engine

Unique principle led to rise of the Stirling hot air engine in varied applications

1930 Hot Air Engine Ad
Watering the herd: Hot air engines found a ready audience in specialized applications – like pumping water in remote locations, as shown in this 1903 ad. The engines were dependable, required little maintenance and could be left unattended for long periods.
Image courtesy of Poway-Midland Railroad. Poway, Calif., www.powaymidlandrr.org