(Our ancestors had a lot to remember when operating a gas stove)
PROPER USE OF GAS STOVE
For Best Results Burners Must Be Kept Clean and in Good Condition- Have Clear Flame
For good results in using a gas stove, keep the burners clean and in good condition, and adjust the air shutters properly, advises the United States Department of Agriculture. The flame should be clear blue and of uniform height. The screw on the air shutter can be adjusted easily with a screwdriver. The flame should be long enough to reach the bottom of the saucepan, but not so long that it will reach its side. The burner should be set as close as possible to the bottom of the saucepan in which food is cooking.
One and one-half inches between the upper surface of the burner and the bottom of the pan is enough, in most cases, and sometimes less will suffice. However, the vessel should not sit so close over the flames as to touch the inner blue cone or core of the flame, for in that case combustion becomes imperfect to such an extent that carbon monoxide, a poisonous gas, may be formed.
(Transcribed clipping from The Advertiser, Moulton, Alabama, July 26, 1923