"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.)
8. Bone Oil is made from the fat obtained by boiling the bones of animals. The finest quality is obtained from the leg bones of recently killed, healthy, young cattle, and the best method of treatment is given as follows[2]:
"Fill a bottle one third full of the oil to be purified. Then pour clarified benzine in small portions upon the oil, close the bottle and shake until the benzine has disappeared. By again adding benzine and shaking, a complete solution of the fat is finally effected. That this has actually taken place is recognized by the contents of the bottle not separating after long standing. The bottle is then exposed to a low temperature for several hours, a solid fat deposits on the bottom, and the lower the temperature the greater is the deposit. Alongside the bottle containing the oil, place another bottle with a funnel, the lower end of which is closed by a cotton stopper; after thoroughly shaking the bottle with oil, pour the contents into the funnel; the fluid portion runs into the bottle, while the solid portion is retained in the funnel by the cotton stopper. The clear solution of bone oil in benzine collected in the bottle is then brought into a small retort which is connected with a thoroughly cooled receiver. Place the retort in a tin vessel filled with water and apply heat. The benzine readily distills off, leaving the purified bone oil in the retort." (66.)
9. Neat's-foot Oil is largely used in the arts, being one of the best of lubricants. The best oil, viz.: that used for clocks etc., is extracted by placing the thoroughly cleaned feet of cattle in a covered vessel near the fire or in the sun. The oil thus obtained is clarified by standing before bottling. (67.)
It was the practice of many olden time watchmakers to allow a large bottle of neat's-foot oil to stand in a position exposed to the direct rays of the sun in summer and to the extreme cold of the winter. Then after two or three years, on a very cold winter day, to pour off such oil as still remained fluid which was preserved for use.
10. Olive Oil has been used as a lubricant since the early days of horology, the older writers giving many methods of treating it. It is obtained from the fruit of the Olea Europea, one of the jasmines, which grows throughout Southern Europe and Northern Africa and other tropical countries.
