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The purpose of this paper is to investigate the effects of liquid carbon dioxide (LCO₂) on grinding of stainless steel.

A factorial experimental approach was used to compare the LCO₂'s performance against grinding under dry air and emulsion coolants.

The experimental results have a great use to practitioners. It was found that under special conditions, LCO₂ proves to be an alternative coolant for grinding of temperature sensitive materials. Furthermore, grinding under LCO₂ conditions produced the lowest tangential force, while the normal forces were close to the values found under emulsion fluid environment. When compared to grinding under dry conditions, LCO₂ coolant was successful in reducing the work piece temperatures. LCO₂ and emulsion conditions inhibit work hardening by reducing material deformation at the grinding zone.

The paper shows that sub‐zero temperature coolants have the ability to bring about lower grinding temperatures than what is typically achieved under conventional fluids.

The El Segundo Division of the Douglas Aircraft Company, Inc., spearheaded by Mr. Delaney, head of department, have evolved a method of sub‐zero quenching and cold cycling which has made considerable savings in many manufacturing departments, improved finishes and prevented many breakages during forming operations. It has been applied to aluminium, steel, titanium, phenolic and other materials. The method has also been applied as a thermo‐shock treatment during machining operations allowing forgings to be machined without distortion, and, for example, chrome molybdenum parts to be band sawn in half previous times. In fact, this material, hardened to 260/280,000 lb/sq.in. was machined on a lathe at spindle speeds and rates impossible to achieve by conventional methods.

THE I.C. engine is a special form of heat engine and, by its very nature, produces excess quantities of heat. Uncontrolled, this heat would soon lead to distortion and damage of mechanical components causing the overall working of the engine to be less efficient and eventually leading to complete breakdown. In the case of small engines, sufficient cooling can be achieved by increasing suitably the external area of the combustion chamber by finning and ensuring a suitable flow of air to these surfaces by ducting and powered fans. These methods are less suitable for larger engines as the extra heat produced would require extensive finning and fans—uneconomical in both power and space. For the majority of i.c. engines the accepted method of cooling is by the transfer of heat through the medium of a suitable fluid.

STELLRAM's first introduction in a new series of tooling ranges is the H‐Elix milling programme specifically developed for the machining of exotic, heat‐resistant materials such as those used in aerospace. Now available ex‐stock from Stellram Ltd of Melksham, Wiltshire, H‐Elix cutters include end and face mills which feature through‐tool coolant supply and cover diameters from 16 to 100 mm. Innovative design coupled with high‐performance inserts result in a cutter which exerts lower forces on both machine tool and component. High positive geometry is ideal for machining difficult materials and maximum advantage is taken in the new range for high efficiency cutting of Titanium, Inconel, Marval, Stellite and other exotics.

This paper presents some of the problems associated with the design and operation of airborne vapour cycle refrigeration equipment, created by the extreme environmental conditions, and indicates where applicable the manner in which the difficulties can be overcome. The design philosophy behind a small high‐speed oil‐free reciprocating compressor is described, by certain fundamental requirements which the designer of airborne cooling equipment must consider. The particular difficulties, associated with effects due to rapid variation of ambient air temperature and pressure, which are peculiar to design and operation of such equipment are then explained. Rapid changes in heat load necessitate careful selection of the type of compressor drive and capacity control, and since extremes of temperature occur during a comparatively short operating cycle, particular attention must be paid to control of condensing pressure, and to prevention of migration of the refrigerant liquid into the low side of the system. The effects of vibration and of high acceleration make it necessary to design the components in such a manner that they can withstand these extreme effects, both while operating and during off‐cycle periods. In conclusion, the author contends that a new field of application for refrigeration equipment is emerging as a result of the more stringent aircraft and missile requirements; considerable theoretical and experimental effort is being devoted to the many problems, and the hope is expressed that continued co‐operation between the Refrigeration and Aircraft Industries may contribute to the more conventional as well as to the more specialized applications of refrigeration.

The authors propose an accelerated method for determination of Mean Hertz Load of E.P. lubricants in order to save time and materials in the lubricant research and testing laboratory. The proposed method is based on a “compensation line” which allows elimination of runs at loads lower than the initial seizure load. Readers interested in securing the whole paper (the following is a shortened version) can refer to this in La Rivista Dei Combustibli, May, 1954.

There are several hundred lubrication oil companies operating in Great Britain today, and a number of these have been operating for fifty years or more. And yet, less than twenty years ago, most of these companies were carrying on their business in the same way as when they began. With the coming of the motor car and motor vehicle in large numbers, most of them turned their attentions to producing motor oils, and in those early days, little science was required to blend very satisfactory grades. Even in the industrial field, bearing clearances were very great by modern standards, and perhaps it may be said that the principal duty of the lubricant was to fill up these gaps.

Examples of the widespread use of Turners ‘Duraglas’ glass fibre reinforcement materials in the aircraft and missile industries have come recently from Australia. The sale of Duraglas products is handled throughout Australia and New Zealand by the various branches of Swift and Co. Ltd., Ashficld, New South Wales.

The Sno‐cat “Haywire” one of four used in Dr. Vivian Fuchs' 2,150 mile journey over Antarctic snow and ice has been presented to the British Petroleum Company in appreciation of the contribution made by the Company to the success of the expedition. The Company provided at their own expense, all petroleum fuels and lubricants for the party from the U.K. as well as that led by Sir Edmund Hilary from New Zealand. They also commissioned at their own expense a film record in colour of the expedition which will be ready by the late summer and B.P's. share of the proceeds from the commercial screenings will be placed at the disposal of the Trans‐Antarctic Expedition.

The Exactor‐Trabon system enables all bearings on one or several machines to be lubricated from a central source. It is so designed that it is impossible for a bearing to be missed. The system may be automatically or manually operated.