https://en.wikipedia.org/wiki/Smudge_pot

In 1907, a young inventor, W. C. Scheu, at that time in Grand Junction, Colorado, developed an oil-burning stack heater that was more effective than open fires in heating orchards and vineyards.[2] In 1911, he opened Scheu Manufacturing Company in Upland, California, and began producing a line of orchard heaters.[3] (The firm still exists in 2018.)[4] The use of smudge pots became widespread after a disastrous freeze in Southern California, January 4-8, 1913, wiped out a whole crop.[5] [6]