~4. The Blubber~, or fat, taken from the jaw of the porpoise or the head of the blackfish was formerly rendered in iron pots over a fire, but the modern method of extracting the oil by steam is said to be much superior. The oil is washed with water by thorough agitation, after which it is allowed to stand for several days, when it is drawn off and the last traces of water removed by distillation. The oil is then subjected to a very cold temperature and pressed through flannel cloths, by which process the "oleine" is separated from the "stearine," the resulting oil being more or less limpid as the former or latter constituent predominates. ~5. John Wing~, of New Bedford, Mass., son-in-law of, and successor to, the late Ezra Kelley, states in answer to inquiries, that their supply of oil comes from the porpoise and blackfish taken during the summer months on the coast of Africa, above the equator; and that they find that this oil contains less glutinous matter than that obtained in and about the St. Lawrence river, which fact he attributes to the difference in the food of the fish, which in turn affects the oil. ~6. D. C. Stull~, of Provincetown, Mass., in answer to inquiries on the subject, has kindly furnished the following information and series of views: [Illustration: _Fig. 1.--Buying a Porpoise from a Fisherman._] "The supply of porpoise-jaw oil and blackfish-melon oil comes mostly from Massachusetts Bay, the trap and gill net fishermen bringing them into Provincetown, sometimes alive, as shown at Fig. 1. The capture of fifteen hundred blackfish, Fig. 2, by the people of Provincetown, Truro and Wellsfleet, was one of the most exciting scenes in the annals of coast fishery. The fish were attracted to these shores by the large quantity of squid and herring, on which they feed. It is estimated that the catch was worth $25,000, some of the fish weighing two tons each. The relative size of a blackfish and a man is shown at Fig. 3. Seafaring men and whaling captains who catch the porpoise at sea, extract the oil from the head and jaw only, and bring it to the factories to be manufactured. "Fig. 4 is a good view of a modern factory. The fat is cut from the head and jaw, (Fig. 5,) washed in fresh water and put into covered tin cans, then into iron retorts, (Fig. 6.) These retorts are then closed, screwed up tightly, and live steam turned on from the boiler. The fat is cooked by steam for five hours, with ten pounds pressure, at 230° F. By this means the crude oil is extracted from the fat." ~7. Sperm Oil~ is the best known of all the lubricants and is, for general purposes, one of the most excellent. The large cavity in the head of the sperm whale contains oil and solid fat, from which the former is separated, without heating, by pressure and crystalization. As it is not at present used to any great extent in horology, a more lengthy description of the method of refining will be omitted. (65.)