Sperm oil and olive oil were used on the machines in the textile industry, as well as upon the leather belts and in the lamps for illumination. Looms also were lubricated with these oils, because they would easily wash out of the finished goods without having stained them. All of these oils were well suited for the mechanical conditions prevailing.
Dr. James Young, in 1847 (Translations of the Royal Scottish Society of Arts, 1865) found petroleum in Derbyshire, England, from which he obtained a heavy lubricating oil by destructive distillation. The opening of the Pennsylvania oil fields, after Drake, in 1859, had demonstrated that petroleum oil could be secured by sinking wells, provided a new source of crude supply to the American refiners operating under Dr. Young's patents; and refinery practice was adapted to the use of petroleum from which to produce the burning oils then so much in demand. Lubri cants were made as a by-product and were being introduced in the manufacturing countries of the world in competition with the established lubricants.
With the primitive and early forms of machinery the lubricant was always applied by hand, the oils being used on the surfaces but once, then dropping on the floor or flying out as mist to be de posited upon the window panes or other cool parts of the machines or buildings which they covered like moist varnish. Oiling by hand is referred to as intermittent lubrication where there is a profuse supply of the lubricant on the surfaces that gradually wears off until the bearing becomes quite dry before the next application. With the flooded bearing, lubrication follows the laws of fluid friction. When the bearings become dry and the surfaces come into contact with each other, the condition changes to that of solid friction, and its attendant dangers of abrasion and stoppage. (See FRICTION.) Beauchamp Tower (see Proceedings of the Institution of Mechanical Engineers, Nov. 1883) found that bath lubrication would give the best degree of lubrication when using lard oil, rape-seed oil and sperm oil, as well as a mineral oil and a mineral grease. His first report contained the following data : From this important basic research work Osborne Reynolds (Philosophical Transactions, 1886) established the fact mathe matically that a well lubricated journal, rotating at a fair speed, becomes automatically separated from its bearing by a film of oil, under pressure, and that the frictional resistance is then due entirely to the viscosity of the oil. John Goodman, reviewing the
results of Tower and other tests of oil on the friction machines of Thurston and Stroudley stated (Transactions, Institute of Civil Engineers, 1886) that the coefficient of friction with the surfaces efficiently lubricated is one-tenth that for dry or scantily lubri cated surfaces.
This combined work of these eminent engineers established rules for the construction of machine bearings and for their efficient lubrication, the result being that machine builders had before them the following knowledge regarding the evolution of the method of applying the lubricants.
(I) Hand-oiling.—The poorest results in regard to lubrication were attributed to this primitive method, in which the oil is applied at irregular intervals and where the bearing is alternately flooded and then dry.
(2) Pad-lubrication.—This method gave better results. The pad was located under the journal, opposite the point of greatest pressure; it carried the lubricant to the bearing surfaces con tinuously by capillary attraction.
(3) Siphon Wick-feed or Drop-oilers.—Slightly better results were obtained because these oilers supplied oil to the film in small amount at frequent intervals.
(4) Bath Lubrication.—The best results were obtained with bath lubrication, only one-tenth the power being required as com pared to hand oiling.
With the rapid introduction of the improved methods of lubri cation and of machine bearing design, suggested by the foregoing basic work, the limit of the economic use of the animal and vegetable oils had about been reached. Further advances in machine construction and operation were possible only through the rapid development and use of the mineral lubricants, because these do not oxidize and form free fatty acids, gums and com pounds, and, in consequence, can be used satisfactorily in con tinous lubricating systems for long periods of time without undergoing detrimental changes. Finally, as the mineral oils came into successful use, there was created a branch of mechanical research engineering now known as lubrication engineering.