On Tuesday at the meeting of the Engineering Society of China in the Royal Asiatic Society's Hall, a paper was read on lubricating oil by Mr. R. T. Brindley Hicks.
The lecturer commenced by pointing out the important part that oil as a lubricant plays in modern machinery. The four kinds of lubricants were then enumerated, viz: vegetable oils, animal fats, water solubles, viz. soaps and mineral oils, the latter being dealt with as being most commonly used for lubrication.
The three principal tests that oils are subjected to were then described: specific gravity, viscosity, flash point.
The specific gravity test was made with the aid of the specific gravity bottle, the oil contents being accurately weighed in a balance and compared with water which is taken as a standard, i.e. distilled water at 60° F. Another method is by the use of an hydrometer which is quicker though less accurate; the results given are, however, quite satisfactory for all commercial purposes. These two tests were described in detail.
The definition of the viscosity of an oil was given and the speaker afterwards went on to explain the apparatus by which actual viscosities of an oil are obtained, and the method of the test.
The instrument most commonly used was the Redwood in the United Kingdom, the Saybolt in the United States and the Engler in Germany.
The flashing point of an oil was explained as the temperature at which it gives off sufficient vapour to ignite momentarily on the introduction of a flame or spark when the oil is heated at a given rate. Open flash point and fire test were also touched upon.
The writer next dealt with the characteristics of the different qualities of oils, dividing them under the following headings: engine oils, cylinder oils, marine oils, machine oils, electricity machinery oil.
The various properties of these oils were compared and it was shown that the viscosities and flash points were required for the different classes of work for which they were especially adapted.
The paper concluded by mentioning Messrs. Wells & Southcombe's paper which dealt with the addition of free fatty acids to reduce the coefficient of friction.
The paper included diagrams of the instruments used in the testing of oils.
A representative attendance of the membership of the Society was present, and a discussion followed the delivery of the paper.
Text read from the printed page and cleaned; old type leaves the occasional error.