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Previous work has suggested that the adhesion between oil and metallic surfaces of an engine could be an important factor in determining crankcase cleanliness. It can be shown that it is only necessary to measure the spreading pressure of an oil on metal in order to get a direct measure of the work of adhesion, Surface tensions of lubrictaing oils vary very little and it can be assumed that the critical film pressure (C.F.P.) obtained with a given apparatus is an acceptable measure of the work of adhesion as well as of the spreading pressure. Oils of similar properties may vary tenfold in their C.F.P's. The addition of additives influences the spreading pressure, the largest increments in C.F.P. being given by dispersant and detergent additives.

FOREWORD COMMUNICATION OF IDEAS and data leads to dross‐pollination in research, which can be as important as the bench work itself. Channels of communication are now highly developed and the growth of specialized symposia and conferences points to the continuing development of this important aspect of research. Those who move about meetings regularly can acquire a balanced understanding of what is going on in the many corners where research is being prosecuted. Those who make a habit of combing, methodically, the technical press can also arrive at some idea of the direction and speed of the currents flowing through a particular subject. There are, however, many technical men who find themselves too busy in their management sphere to keep abreast with either meetings or the scientific journals.

DESPITE the quite extensive literature on foam, the mechanism of its formation and decay does not appear to be widely appreciated. Most fundamental research has been orientated towards maximum foam in aqueous solutions, whereas the desire in aircraft engines is for minimum foam in oil ‘solutions’. Further, the numerical results obtained experimentally depend on the details of experimental procedure, which makes correlation of existing data very uncertain.

AS air is a compressible fluid, a decrease of pressure occurs with increase of altitude (FIG. 1.) This change gives rise to anoxia or altitude sickness (due to lack of oxygen), expansion of the gas in ear or abdomen and ‘bends’ or decompression sickness. For these reasons (and also because of the low temperature and humidity) it is necessary to protect passengers intending to fly at high altitudes by placing them in a special cabin in which a suitable pressurized atmosphere can be maintained.

IT MAY reasonably be asked “why should metalworking lubricants be considered as a class on their own?” Apart from convenience of classification, there are at least three good reasons for doing so:

This article shows how a rational approach to the selection of cutting fluids can be made from an appreciation of the principle factors and mechanisms involved. Attention is also drawn to the benefits of using the same grade of oil for machine lubricant and cutting fluid where this is practicable.

The Institute of Petroleum held a Symposium on Gear Lubrication at Manson House, 26 Portland Place, London, W.1. on February 13th. This was timely in view of the growing use of hypoid gears for automobile use and the need for standardized testing procedure for hypoid lubricants. The papers dealt also with gear lubrication generally, including worm gearing. An abstract of all the papers is given here. Many of the papers presented were highly technical and were intended to be of more interest to research workers and to lubrication technologists in the trade. Several of them, and some parts of all of them, however, brought out many practical points.

MOST modern internal combustion piston engines when under power have such a contented purr that many people contend that no serious lubrication problems of a technical variety remain to be solved, and that the only problems worth mentioning are those which are solely of an economic nature. Such views are, in their own way, flattering to the oil manufacturer who has striven hard, in conjunction with engine manufacturers, to bring these engines to a high pitch of reliability in a relatively short time. However, complacency in a world of change can be a dangerous thing.

The Petter AV1 single‐cylinder 4‐stroke compression ignition engine is frequently used by oil companies and additive manufacturers for screening tests for additive lubricating oils because it can obviate the long and expensive Caterpillar procedure. The oil tests on Caterpillar engines take from 3 to 4 weeks and spare parts, which require dollars, are costly. The Petter AV1 engine test, which has been modified from the standard unit to make it suitable for this work and to more closely simulate the conditions to which the oil is exposed in the Caterpillar engine, takes 120 hours. The modified test is the I.P. AT/4, as modified by the Engine Tests of Lubricants Panel of the Institute of Petroleum.

A Symposium on Metal Cutting Oils was held by the Institute of Petroleum on March 19th, and as usual where lubrication subjects are discussed, was well attended. Most valuable papers were presented by many who specialize in this field both in connection with research as well as the industrial field. The Symposium was divided into two sections. Metal Cutting and Metal Forming respectively. We give here extracts from some of the papers presented in the first section and shall cover the second section in our next issue.