Investigations into the creep of metals were set in motion by R. W. Bailey about 1925 and have contributed much to the design of present-day power plant, which requires alloys that will withstand temperatures far above those used a few years ago. For instance, the work led to the introduction of chromium-molybdenum bolt steel and of molybdenum-vanadium steel for important parts of gas and steam turbines, including steam piping. The latter alloy, familiar to the Company for more than ten years, is now becoming generally recognized here and in America as the only type of ferritic steel that can be used with the highest steam temperatures and pressures in combination.

Later studies, chiefly by A. M. Roberts, with a form of temperature-controlled creep-tensile testing machine enabled the first batch of creep-testing units to be designed. These have been in use since 1928, and the extensive study of creep in the following years has been vital to the development of jet engines and gas turbines.

In 1925 a six-element recording electromagnetic oscillograph was constructed and installed, complete with dark room, near the main test beds in the works, forming the nucleus of the present oscillographic section. This is only one of the many pieces of testing apparatus that have been developed in the research department for works use. Examples are apparatus for the measurement of air flow in large turbogenerators, resistance test sets, short-circuit coil testing sets, iron loss test sets, temperature indicators for transformer windings, an harmonic analyser for direct measurement on electrical machines, and a.c. bridges for power measurement.

In 1926 came the brilliant discovery by C. R. Burch of the low-vapour pressure oils and greases known as Apiezon compounds. Distillation was a process that had always interested him, so it was natural that the sight of a tank of 'steaming' transformer oil, the degassing of which he had been asked to investigate, should reawaken the desire to work on distillation—this time, on vacuum distillation. "No chemist", he had been cynical enough to say, "knows how to make a vacuum, and no vacuum worker has been interested in distillation except Hevesy, and he has not applied molecular distillation to organic chemistry. It would be rather jolly to distil mineral oil under really high vacuum, in fact the best vacuum possible". In this spirit Burch devised a molecular still and obtained distillates having extremely low vapour pressures and therefore capable of being used for high vacuum impregnation. Thus encouraged he developed larger experimental stills incorporating the principles of molecular distillation; an early commercial application was the concentration and separation of vitamins in fish liver oils, where the high temperatures normally required would have destroyed the vitamin content.