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THURSDAY, SEPTEMBER 7, 191 1. 



THE PARSONS STEAM TURBINE. 

 The Evolution of the Parsons Steam Turbine. By 

 Alex. Richardson. Pp. xix + 264+173 plates in the 

 text. (London : Offices of Engineering, 1911.) 

 Price 2 is. 



IN this volume there is contained an authentic record 

 of steps taken in the development of a great 

 invention. Lord Kelvin once described the work done 

 by the Hon. Sir Charles Parsons in connection with 

 the steam turbine as ranking in importance with the 

 work of James Watt. The council of the Royal 

 Society of Arts in awarding the Albert medal for 191 1 

 to Sir Charles Parsons, for his experimental re- 

 searches into the laws governing the efficient action 

 of steam in engines of the turbine type, and for his 

 invention of the reaction type of turbine, stated that 

 by means of its practical applications the production 

 of mechanical power had been cheapened, economy of 

 fuel and higher speeds had been obtained in steam- 

 ships, and the problem of rotary engines, which long 

 had baffled many other inventors, had been solved. 

 This expression of opinion by a council which includes 

 many eminent engineers and physicists will command 

 universal assent : it also emphasises the value attach- 

 ing to the record of research and achievement which 

 has been undertaken and completed by the author of 

 this book. The principal facts were already available, 

 having been published from time to time in the Pro- 

 ceedings of engineering societies and in engineering 

 journals. But it is equally true that by collecting 

 and arranging such materials the author has done a 

 useful piece of work, and done it well. Not merely 

 has he told the story in an interesting way, but he has 

 secured the aid of Sir Charles Parsons and several of 

 his colleagues, and has thus made the record complete, 

 adding many new facts. One characteristic of the 

 book deserves special mention : its style and method 

 will enable readers to master the main steps in the 

 development- of the steam turbine, even though their 

 knowledge of engineering is small. On the other 

 hand, skilled mechanical engineers can find therein a 

 wealth of illustration and a mass of valuable data 

 obtained by Sir Charles Parsons and his assistants 

 in their long and varied experimental researches. 



It scarcely seems credible, but it is the fact, that so 

 lately as 1884 Sir Charles Parsons began work on his 

 first steam turbines, or that it was ten years later 

 before trials were made with the first steamship 

 driven by turbine machinery. During the earlier 

 period progress was naturally slow : many difficulties 

 had to be overcome, and outside or accidental causes 

 of delay occurred. The inventor was not daunted by 

 these difficulties, and he fortunately obtained support 

 from friends who had confidence in his ability to face 

 and solve problems which had baffled previous in- 

 vestigators. Sir Charles Parsons, like many other 

 inventors, discovered that although many previous 

 attempts had been made to construct steam turbines, 

 little exact or trustworthy data had been put on record 

 by his predecessors. Consequently it became necessary 

 NO. 2184, VOL. 87] 



for him to arrange and undertake further and costly 

 experiments. The system which had previously 

 found most favour with his predecessors was that 

 known as the "impulse type" of turbine, in which 

 rotary motion was produced by the impact of steam 

 jets on suitably shaped cavities situated at the peri- 

 phery of revolving wheels, or by the reaction of steam- 

 jets issuing into the atmosphere. Sir Charles 

 Parsons originated the idea of splitting up the fall in 

 steam pressure, by employing a great number of 

 wheels or turbines placed in series. To quote Mr. 

 Richardson's words, Sir Charles Parsons made 

 "the assumption that in each turbine the action would 

 approximate to that in a turbine using an incom- 

 pressible fluid such as water, and that the aggregate 

 of such simple turbines, which together constituted 

 the complete machine, would give an efficiency 

 approximating to that obtained in water turbines." 



This fundamental assumption proved to be accurate ; 

 but when the fact had been established its embodi- 

 ment in successful machines which were indi- 

 vidually of large power demanded great skill and 

 patient experiment. Unfortunately, after the first re- 

 action turbines had been made and proved successful, 

 difficulties of a business nature interfered for some 

 time with the development of the system. Sir Charles 

 Parsons then introduced turbines of the "radial flow " 

 type instead of the longitudinal flow type with which 

 his name will ever be associated. The first turbine 

 was produced in 1884 and was applied to the genera- 

 tion of electricity, the design of the dynamo being 

 modified by the inventor so that it might be suitable 

 for association with turbines running at very high rates 

 of revolution. These early turbo-generators were of 

 comparatively small power and were relatively waste- 

 ful in steam consumption, although in their mechani- 

 cal details they were the pioneers of the enormously 

 powerful machines now in use on land in electro- 

 generating stations. In 1885 a turbo-generator of 

 four-kilowatts power required 200 lb. of steam per 

 kilowatt-hour. In 1910 turbo-generators of 5000 kilo- 

 watts were produced by Sir Charles Parsons, and the 

 steam consumption per kilowatt-hour was but little 

 more than 13 lb. Limits of space prevent any detailed 

 explanation being given of the successive improve- 

 ments which have led to this remarkable economy in 

 steam consumption; but readers desirous of tracing 

 these steps will find every information in the pages of 

 the volume under review. 



In the application of the Parsons steam turbine to 

 ship propulsion even more remarkable progress has 

 been made. The first vessel (the famous Turbinia), 

 completed in 1897, was a hundred feet long and 

 weighed about forty-four tons; her engines developed 

 2300 horse-power, and her speed was 32! knots for 

 runs of short duration. Ten years later the great 

 Cunard trans-Atlantic steamships Mauretania and 

 Lusitania were driven by turbine machinery develop- 

 ing 74,000 horse-power, the length of the vessels being 

 about 785 feet, their weight 40,000 tons; and the 

 mean speed on their fastest trans-Atlantic voyages 26 

 knots. The latest armoured cruisers of the Lion class 

 in the Royal Navy furnish the most notable illustra- 



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