The mass gradually assumes a murky yellow appearance as the oil is made free. The man in charge of melting uses a bath thermometer constantly and regulates the temperature of the water in the jacket by the admittance of cold water to chill it or steam to warm it so that the temperature of the melting oil does not exceed 156° F. It usually takes 1¹⁄₂ hours to properly melt the contents of a full kettle. When the melting is complete the stirrer is raised out of the oil and allowed to remain raised while the oil is settled. =Settling the Oil.=--When the oil comes to rest about twenty pounds of fine salt is scattered over the surface, thrown in moderate handfuls so as to sprinkle the entire surface. This salt in settling clears the oil by carrying down the floating fibre by mechanical as well as chemical action. The oil usually has a scum on top and this is gently skimmed off and saved as a bottom for the next kettle. After settling about fifteen minutes the oil is run off by gently lowering the hinged pipe, the oil as de-canted is passed to the clarifier. When the pure oil is run as low as can be conveniently done without carrying off any scrap of settlings, the oil laying on the surface of the water and sediment in the bottom is passed to some receptacle and sent to the pressure tanks. The kettle is well scrubbed, made clean and the skimmed bottoms deposited ready for filling again with hashed fat. [Illustration: FIG. 55.--SETTLING KETTLE FOR OLEO OILS.] =Clarifiers or Settling Kettles.=--Each kettle is provided with two clarifying or settling kettles. These are cone-shaped tanks in which the oil from one melting kettle is deposited. The oil is allowed to stand as long as possible in a quiet state and the sediment or fibre collects in the bottom of the cone. This is withdrawn at the bottom at frequent intervals so as to free the oil from sediment and dirt. The temperature of the oil carried in the clarifiers is 140°, kept uniform by use of warm water in the jacket. After settling the oil about two hours it is drawn to the seeding trucks. Cotton flannel bags are usually put on over the outlet pipe so as to strain the oil and collect any floating pieces of tissue that would otherwise pass to the seeding truck.