Warren S. Johnson

Warren Seymour Johnson (November 6, 1847 – December 5, 1911) was an American college professor who was frustrated by his inability to regulate individual classroom temperatures.

It appears that he had only limited formal educational training – but supplemented his knowledge with self-study of scientific subjects.

It was a bi-metal coiled thermostat with a mercury switch, which could be used to ring a bell to alert the fireman to open or close the heating damper.

[3] Johnson continued to invent additional control devices, as well as products such as chandeliers, springless door locks, puncture-proof tires, thermometers, and a hose coupling for providing steam heat to passenger railcars.

For about three months, Lee de Forest, who eventually went on to design the audio vacuum tube that provided the breakthrough for radio, worked on the project with Johnson.