No refined petroleum oil for illuminating purposes shall be manufactured, sold or offered for sale by any person, firm, or corporation, within the Commonwealth of Pennsylvania, having a fire test lower than one hundred and ten (110) degrees, Tabliabue's open cup, according to the following formula: Fill the water-bath of the apparatus with water of a temperature under eighty degrees Fahrenheit; fill the oil-cup of the apparatus, to a point one-quarter of an inch below the top of the same, with the oil to be tested; when the said oil is at a temperature under eighty degrees Fahrenheit, suspend a round bulb thermometer, graduated in single degrees Fahrenheit, so that the bulb is just submerged in the oil to be tested, and is in the center of the surface of the oil; heat the water-bath with a lamp, the flame of which can be regulated, so that the temperature of the oil to be tested shall rise at the rate of not less than two nor more than three degrees Fahrenheit a minute, until the temperature of ninety degrees Fahrenheit is reached. At this point remove the lamp, and when the temperature of the oil to be tested, as indicated by the thermometer, has reached ninety-five degrees Fahrenheit, try for a flash with a small bead of fire passed slowly over the surface of the oil in the cup and within a quarter of an inch of said surface. If the oil does not take fire and continue to burn, replace the lamp under the water-bath, thereby heating the oil at the previously described rate until the temperature of ninety-five degrees Fahrenheit is reached; then again remove the lamp, and, when the oil has arisen to the temperature of one hundred and two degrees Fahrenheit, try for flash and burn in the same manner as at the temperature of ninety-five degrees Fahrenheit. Repeat these operations, trying for the burn at seven-degree intervals, until the oil in the cup takes fire and burns continuously. The temperature at which such continuous burning takes place shall be considered the “Fire Test,” and the temperature at which the vapors from the oil first ignite, but do not burn continuously, shall be considered the “Flash Test.”