HISTORY OF TECHNOLOGY

1985 Parsons Memorial Lecture1884: the rebirth of steam power

N.C. Parsons, MA, CEng, FIMechE

Indexing term: History, Electric power generation

Abstract: In the early 1880s the steam engine wasconsidered to be obsolescent and it was predictedthat the internal combustion engine wouldbecome the more efficient machine of the future.Both engines relied on the conversion of recipro-cating to rotary motion, and thus their speed andoutput were limited by inertial forces. The papersuggests that in 1881 Parsons foresaw that theinfant market for distributed electricity woulddevelop into one of immense size requiring primemovers of vastly increased powers, and that hisinitial ideas were centred on a rotary internalcombustion engine. The paper describes the 1884Patents, their practical details and their widecoverage. Parsons had to circumvent them whenhe lost their use in 1890, and it is a measure of hisimmense determination and courage that he per-severed both to win through to the ultimately suc-cessful exploitation of his inventions in the field ofelectrical generation, and also to establish hissteam turbine for marine propulsion. Any majorinnovation requires a long term and absorbsmuch effort and money before its exploitationyields financial returns. This fact is as true todayas it was at the end of the 19th century.

1 Introduction

The choice of subject for this paper is very wide, beingonly restricted to any of the subjects in which Sir CharlesParsons was interested. Sir Charles was a true Victorianengineer and his curiosity extended into many fields, ascan be judged by the subjects chosen for previous lec-tures. His interests were so diverse that they have tendedto distract attention from his main achievement: thedevelopment of the first practical steam turbine and high-speed electrical generator.

In the 54 years since Sir Charles's death, his name andachievements have largely been forgotten in the mind ofthe general public. Indeed, a recently published diction-ary of biography [1] accords him six lines as comparedto the 30 lines for a 16th century English Jesuit priest ofthe same name who did not even achieve the distinctionof martyrdom; Newcomen merits seven lines, Watt 44,

Paper 5150A (S7) first received 7th January and in revised form 6thMay 1986The author can be contacted at Pigdon House, near Morpeth, North-umberland NE61 3SE, United Kingdom

Faraday 60 and Ferranti is not mentioned: such is thecapricious ranking of famous engineers of the past. WhenParsons is remembered it is usually because of the news-worthy event of Turbinia's irreverent irruption into theprestigious and very formal Spithead Review of 1897 forQueen Victoria's Diamond Jubilee or as a brilliant eccen-tric engineer who tried, and failed, to make artificial dia-monds. But during his lifetime he was regarded as aleading, or even the leading, engineer of his age; and heshould still be so regarded. He laid the foundation for thecentral generation of electrical power which we accept asone of the bases of civilisation as we know it today. Isuggest that he is also the progenitor of today's gasturbine in that his idea of pressure compounding, asapplied in his steam turbine, seems to have been initiallyconceived for a gas turbine cycle.

The title of this paper may appear to be mechanicalbut it has a blood relationship with electrical engineering.Presumably, as for birth, the process of rebirth requires amother and a father. In the case of the steam turbine, themother, the necessity of invention, was the introductionof the incandescent electric lamp; the father was the welldeveloped use of steam power and the reciprocatingsteam engine which had evolved over almost 200 years.Probably the immediate prospect of central electricalgenerating stations and distribution systems for lightingwith the future prospect of a distributable form of bulkpower prompted Parsons to recall that 'about the year1884, circumstances being favourable, I determined toattack the problem of the steam turbine and of a very-high-speed dynamo and alternator to be driven by it' [2].

In the first Parsons Memorial Lecture [3] Sir FrankSmith pointed out that in 1881 such leading engineers asLord Armstrong and Sir Frederick Bramwell consideredthe steam engine to be obsolescent. Some 60 years earlierCarnot had described the ideal thermodynamic cycle inwhich the efficiency of an engine was primarily related tothe upper temperature of its cycle. Thus it was consideredthat the internal combustion engine, using gas or pet-roleum as a fuel, would ultimately be capable of achiev-ing a higher efficiency than the lower-temperature steamengine, and that, irrespective of unit size, it wouldbecome the prime mover of the future.

Today, more than 100 years later, the steam turbineand direct-coupled high-speed generator is the onlymachine capable of being built in the large unit ratingsrequired to generate electricity in central thermal powerstations. Parsons's contributions to development in thefield of electricity are often underrated and the majorcontribution, the high-speed generator, was welldescribed by Mr. Horsley in the 1964 Parsons MemorialLecture [4]. Other contributions include improvements

IEE PROCEEDINGS, Vol. 134, Pt. A, No. 4, APRIL 1987 359

to arc lamps and his work with The Sunbeam LampCompany to make large incandescent light bulbs in the1880s. In fact Parsons filed more than 50 Patents for elec-trical generators and other electrical appliances.

The aim of this paper is to describe the saga of howParsons pioneered the development of his major inven-tion against heavy odds over a long period in the fields ofelectrical power generation and of marine propulsion; tosuggest the route by which he invented the steamturbine; and finally to reflect on the process of exploita-tion of invention.

1.1 Background of electricity in the 1880sFollowing its first application in lighthouses in 1856, thearc lamp was progressively developed for the purpose ofartificial lighting, but applications were limited to illumi-nating large buildings and open spaces; domestic andother commercial lighting relied on the fish-tail gas light.Consequently the growth in demand was modest until adramatic increase occurred following the introduction ofthe incandescent electric lamp by Edison and Swan in1879.

Until 1888, the creation of electrical supply companieswas bedevilled by bureaucracy and parliamentary legisla-tion. Apart from some notable exceptions, such as Bright-on (1882), electrical generation, therefore, catered only forlocal systems requiring small unit ratings for generators.

The prime mover was the reciprocating steam enginewhich had been progressively developed to a high degreeof sophistication. It suffered, however, from its relativelylow rotational speed because of the limitation of inertialforces. Steam engines of established design ran at speedsup to little more than 100 rev/min, whereas electrical gen-erators ran at up to about 1500 rev/min. The alternativeswere either to use belt or rope pulleys to gear up thespeed of the engine, or to direct couple the engine to abulky and less efficient generator. As the unit ratingincreased, the maximum speed of the steam enginedecreased, and the problem would become even moreacute.

The ultimate solution was clearly the development ofthe engineers' dream of an engine using pure rotarymotion. Parsons must have foreseen that the continuingand rapid growth in demand for electricity would makesuch a solution a necessity in the future.

Such a necessity, however, was slow in developing andfor many years the needs of the market for the largestgenerators could be met by existing technology. Theestablishment of Parsons's inventions, therefore, provedto be a time-consuming and hard-fought battle, requiringgreat determination and courage against adversity. Hemodestly expressed his self confidence in ultimate successas 'if your development has been carried out step by stepand always properly analysed, then, when you come to abig jump into the unknown, courage and your earlierwork will take you safely over.' [5]

2 Invention and early development of steamturbine and high-speed generator

2.1 1884-89There are only tantalising glimpses of the early develop-ment work prior to the 1884 Patents, and it is aston-ishing to reflect on the degree of completeness in theconcepts embodied therein.

The timescale is equally baffling. He was busilyoccupied at Kitson's in Leeds on Rocket-propelled tor-pedoes until, on the 1st January 1884, he joined Clarke

Chapman, of Gateshead, as the junior electrical partner.Clarke Chapman were established marine engineers andthus provided an ideal entrance to the rapidly developingnew market for electric lighting in ships and the need forrobust, compact and simple electrical generatingequipment. It is known that he conducted a series ofexperiments with plain shafts running at speeds up to40000 rev/min to establish that whirling could be con-trolled by flexibly mounted bearings having a high degreeof damping. There also exists a notebook [6] entitled'Gas engines' started on the 20th October 1881 and con-taining a series of not readily translatable calculations.Later in this paper this notebook will be referred to ingreater detail.

Yet, after less than four months with Clarke Chapmanand Parsons he filed, on the 23rd April 1884, the twocomprehensive Patents, 6734 and 6735, for the first prac-tical steam turbine and high-speed generator.

The separate inventions claimed in these Patents, andin Patent 14723 of 1884, were:

(a) a multistage axial-flow reaction turbine(b) opposed steam flows to balance end thrust(c) elastically mounted and frictionally damped bear-

ings to limit vibration{d) a shaft-mounted oil pump(e) a shaft-mounted vacuum air pump to prime the oil

pump(/) a speed control system also using the vacuum air

pump(g) a wave wound armature(h) commutator segments end tightened on to dove-

tailed steel rings(i) cooling the armature by oil(/) a removable commutator(k) a multistage axial compressor(/) a gas turbine.

In addition, the specifications describe other practicaldetails such as methods of forming blades, control ofsteam leakage, forced lubrication, and a centrally locatedoil reservoir to offset the effect of pitch and roll in ships.The latter detail indicates the immediate market that hehad in mind in 1884.

These features are illustrated in Figs. 1, 2 and 3. Theyare mentioned individually partly to illustrate the detailin which Parsons had considered the design of such anovel machine before building the prototype, and partlyto set the scene for later events in the saga.

The prototype machine (Fig. 1) was of small output,only about 10 hp, but it ran at the unprecedented speedof 18000 rev/min, which was more than ten times greaterthan any existing generator. His choice of such a smallmachine was influenced by the cost of a few failures beingnot too great, but in the choice of speed he may well alsohave had in mind the principle of dynamic scaling,whereby it would establish the levels of stress and othercharacteristics of a machine running at 1800 rev/min andhaving an output of 10 x 102 hp or 750 kW. So theconcept was certainly capable of development to largerunit sizes!

During his time at Gateshead, 1884-89, Parsons soldabout 250 turbines; most were for electric lighting but afew were for electroplating. The majority of the lightingapplications were for ships, but some were for privateland-based plants. As mentioned earlier there were fewcentral supply companies and those that there wereunderstandably chose to use traditional plant for whatwas an inherently hazardous investment.

360 1EE PROCEEDINGS, Vol. 134, Pt. A, No. 4, APRIL 1987

To establish his machines in power stations, Parsonsbecame a founder member of the Newcastle and DistrictElectric Lighting Co. Ltd., which was registered on the14th January 1889. In anticipation, four 75 kW single-phase turbo-alternators were ordered in 1888 for theForth Banks Power Station, the first two sets being com-missioned in January 1890.

As with all Parsons turbines built up to that time,those at the Forth Banks station exhausted steam to

atmosphere. This limitation, combined with the inefficientblade profiles, resulted in the steam-turbine-driven gener-ators being considerably less efficient than those drivenby condensing reciprocating steam engines, despite theadvantage of a direct-coupled high-speed generator. Thesteam-turbine generator, however, had the advantages oflower capital cost and greater compactness; it needed lesssupervision and maintenance; it consumed less lubricat-ing oil; it ran with much less vibration; it could better

i speed control system

Fig. 1 Prototype steam turbine generator (Science Museum)

vacuum air pump

shaft-mountedoil pump

frictionally dampedflexible bearing

Fig. 2 Diagrammatic illustration of design features of machine number 1

commutatorsegments

dynamo

Fig. 3 Diagrammatic illustration of 1884 armature

IEE PROCEEDINGS, Vol. 134, Pt. A, No. 4, APRIL 1987 361

match sudden changes in load; it could more easilyaccommodate priming, and it required much simplerfoundations than did a reciprocating steam engine. Butthe major economic advantage was that, because it ran ata steady speed and therefore supplied a steady voltage,the life of an incandescent lamp was up to five timeslonger. True, more coal was needed to provide a givenelectrical consumption, but coal cost only five to six shil-lings per ton, which was much the same as the cost of anew incandescent lamp.

2.2 1890-1894Probably because of differences of opinion as to the needto expend yet more money on exploiting the steamturbine, Parsons terminated his partnership with ClarkeChapman on the 31st December 1889 and formed hisown company to develop and sell his machines. Thereasons for the break up are not documented, but feelingsmust have run high because Clarke Chapman retained,as was their right, the Patents taken out during theperiod of the partnership, demanding a very high pricefor their transfer even though they showed no intentionof exploiting them. Faced with the denial to use theessential core of his inventions, a lesser man might wellhave abandoned the struggle. But not so Parsons. One ofhis aphorisms was 'If in your development you come to astone wall, don't try to batter your way through it. Thereis always a way over the top or underneath or round theend of it '[5].

The vital patented claims of which he had lost the useare those lettered (a) to (h) in the previous list. It isinstructive to review them individually and to see how hecircumvented them.

(a) A multistage axial-flow reaction turbine: Althoughthe option of 'radial' flow was included in the provisionalspecification, it was omitted from the complete specifi-cation. After a disastrous experiment with inward radialflow, he successfully developed an outward radial-flowdesign, for which, tongue in cheek, he claimed superiorefficiency.

(b) Opposed steam flows to balance end thrust: Endthrust would be greater in a radial than an axial-flowdesign; a single flow design was adopted with a dummybalance piston and an elastically mounted thrust block tooffset any residual end thrust. Within nine months of thefirst Patent for this feature, he added axial adjustment tothe thrust block to control blade tip clearances, andthereby limit tip leakage.

(c) Elastically mounted and frictionally damped bearings:'Oil damped' instead of 'frictionally damped' providedthe solution to this problem. It was a blessing in disguisebecause the frictionally damped design gave trouble infretting of the surfaces of the washers.

(d) A shaft-mounted oil pump: This was replaced by areciprocating oil pump driven by a wormwheel off themain shaft.

(e) A shaft-mounted vacuum air pump to prime the oilpump: This was no longer required as the reciprocatingpump could be positioned below the level of the oilreservoir.

(/) A speed control system: This clearly posed a verydifficult problem. The patents under this heading takenout in 1890 and 1891 [7] show a variety of complicatedschemes. A centrifugal governor working on a cam drivenoff a lay shaft, a reciprocating air pump with variableleak off and an electrical switch which made, and broke,many times a second were devised and patented before hehit on the simple solution embodied in 'gust governing',

the principle of which was retained for more than 30years and which had the advantage of continuous oscil-lation of the steam valve so the risk of sticking was mini-mised.

(g) A wave wound armature(h) Separate commutator segments: The only solution

was to revert to a well-established design, and Parsonschose the Gramme Ring dynamo/alternator, that headapted for speeds up to 5000 rev/min, even though itwas wasteful in respect of use of material and efficiency ashalf the winding was inactive.

These features are shown in Fig. 4.Parsons now embarked on the task of developing a

less-than-optimum steam turbine as a superior com-petitor in efficiency to the established reciprocating steamengine, while the possessors of the vital principle of axialflow sat on it immobile. Constrained as he was he never-theless succeeded. After building and testing a prototypecondensing turbine, subsequently installed at his ForthBanks Power Station, he became an investor in the Cam-bridge Electric Lighting Co. in order to supply steamturbo-alternators to a second supply company. Theseturbines, rated at 100 kW, exhausted to condensers at avacuum of 673 mm Hg. The official tests, independentlysupervised by Professor Ewing, demonstrated the steam-turbine-driven sets to be more efficient than those drivenby the best available reciprocating steam engine. Thiswas in 1891, but instant success still did not follow.

In 1893, Parsons supplied machines to the Scarbo-rough Electric Lighting Co. but, once again, only becausehe was a substantial investor in the company. So, howwas he ever going to break out?

2.3 1894 and thereafterAfter a long and tortuous legal case, Parsons recoveredthe use of his 1884-89 Patents for the 'nominal' sum of£1500: equivalent to some £60000 today. Although hethereby became free to develop alternative solutions tocommon problems, the only features of the 1884 Patentsthat he chose to prefer over his subsequent work were theprinciple of axial flow in the turbine and the method ofwinding the alternator. So, albeit unintentionally, ClarkeChapman had done a service to the development ofBritish innovation.

Like so much of history, the next event in the saga wascompletely unplanned and ultimately proved to be deci-sive.

In 1894, the Metropolitan Electric Supply Co., ofLondon, who had installed ten Willans reciprocatingsteam engines in its Manchester Square Power Station,was faced with a legal injunction to reduce the noise or tocease operation within 18 months. In desperation thecompany approached Parsons to install steam-turbine-driven sets as a solution to the problem, and thus one,subsequently two more, 350 kW machines were orderedfor that station.

The success of the venture led to further sets beingordered by the Metropolitan Supply Co. for new stationsand other supply companies began to follow suit.

At this point it is instructive to consider the growth ofthe market for electricity. Back in 1880 it was almostentirely used for lighting. Other applications, at least inBritain, were slow to make significant contributions tothe sales of electricity. By 1890 electric flat irons, fans,immersion water heaters and an 'electric rapid-cookingmachine, that boiled a pint of water in 12 minutes' wereavailable and practical experiments with electric cooking

362 IEE PROCEEDINGS, Vol. 134, Pt. A, No. 4, APRIL 1987

were being started. Electric motors, in general applica-tion, were in their infancy but in other countries electrictraction was developing. Parsons wrote in 1895: 'At thepresent time the mileage of electrically worked tramways

2.4 Marine applications from 1894A paragraph in Patent 6735 of 1884 states: 'A com-

pound motor such as described may be applied to marinepropulsion, but as the velocity is necessarily high, it will

radial flow

reciprocatingoil pump

Fig. 4. 100 kW turbine generator for Cambridge Supply Company 1891

and railways in the United States is stated to be equal toone half that of the railways in Great Britain. In theUnited Kingdom there are only some six or eight electri-cally worked lines of short length' [8]. He ascribed this toBritain's objection to overhead conductors, but anotherinfluence was the Tramways Act of 1870 that requiredcompulsory purchase of private tram companies by localauthorities after 21 years.

Fig. 5 shows the growth of sales of electricity in Britainbetween 1895 and 1913 [9]. Consequent on the relativelyslow growth in the size of individual supply systems, themaximum size of a single generating set increased onlyslowly. The reciprocating steam engine thereforeremained a well-established choice as the prime moverbut its size and weight were proving a disadvantage.When Walker and Wallsend Union Gas Co. built itsfirst electrical generating station at Neptune Banks inNewcastle (opened in 1901) the consultant Charles Merz,an outstanding innovator himself, recommended install-ing 800 hp reciprocating steam engines because the pro-vision of established machinery would reassure theshareholders, among whom were many Tyneside ship-builders. These machines are in the background of Fig. 6;the 1500 kW steam-turbine generator in the foregroundwas installed in 1902. The larger the rating the greaterwas the difference in size of the alternatives (Fig. 7). Thefour 3500 kW reciprocating engines commissioned atGreenwich in 1906 were the last large reciprocatingengines to be installed in Britain; 22 years after theinvention of the first practical steam turbine and high-speed generator; almost the same length of time that usedto be considered appropriate for an infant human toachieve its majority!

be necessary to place several fine pitched screws on theshaft...'.

To be reasonably efficient at small powers, turbineshad to run at many thousands of rev/min whereas pro-pellers of the time ran at tens of rev/min. Until Parsonscreep cut gearing was introduced in about 1910, gearwheels were too inaccurate to transmit large powerswithout making prodigious noise; thus for marine appli-cation the turbine had to be directly coupled to the pro-peller. Parsons, therefore, had to wait until he haddeveloped designs for substantial powers and it was notuntil 1894, when machines of 150 kW (or 200 hp) were inservice, that he felt confident to take 'a big jump' to a2000 hp turbine driving a propeller at 2000 rev/min.

The Marine Steam Turbine Company was registeredon the 25th January 1894 'to provide the necessarycapital for efficiently and thoroughly testing the applica-tion of Mr. Parsons's well-known steam turbine to thepropulsion of vessels'.

The building and development of 'Turbinia' throughmany major setbacks, that would have discouraged mostother engineers, to the famous dash through the line ofwarships of the major national navies assembled for theSpithead Review in June 1897 has already been describedelsewhere; it is indeed one of the purple patches of engin-eering history. I do not intend to repeat the story indetail.

I would, however, draw attention to the fact that theconcept and detailed design of every aspect of the vesselwere in the hands of one man, who could truly be termedThe Compleat Engineer^-As a result, such a major inno-vative prototype achieved success in less than three and ahalf years.

IEE PROCEEDINGS, Vol. 134, Pt. A, No. 4, APRIL 1987 363

Contrary to popular legend, Turbinia's appearance atSpithead probably had the connivence of some of themore forward-thinking officers in the Admiralty. It isironic to reflect that her run at a speed of over 34 knotswas made at the request of Prince Henry of Prussia [10].The Times, as ever true to British form in its suspicion of

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Fig. 5 Growth of electricity sales 1895-1913Semilog scale: slopes indicate rates of growth

innovation, sounded a cautionary note by observing thather speed 'was accompanied by a mighty rushing soundand by a stream of flame from her funnel at least as longas the funnel itself ... [These are serious defects for]torpedo boats for whose operations silence, secrecy andinvisibility are indispensable' [11].

The rate of development of marine turbine propulsionwas astonishing. In 1907, only ten years after the Spit-head Review, RMS 'Mauretania' had her trials with70000 hp of turbines. A classic photograph (Fig. 8) showsthe two ships side by side. There was, however, anotherserious competitor to supersede the reciprocating steamengine at lower powers; by 1912 Sulzer employed about4000 men in their diesel engine factory at Winterthur.Today, for all but the largest powers, the diesel engineand the gas turbine reign supreme in the field of marinepropulsion.

2.5 Aeronautical applicationsA review of Parsons's work on steam would be incom-plete without mention of his venture into flying machines[12]. This was in 1893, three years before Langley'smodel aeroplane flew across the River Potomac.

He did no further experiments on flight although hemaintained his interest in the developments of others. Hisand Langley's model are probably the only two flyingmachines to have been powered by steam.

3 Genesis of idea of steam turbine

In the first Parsons Memorial Lecture Sir Frank Smithsuggested that the three main influences that inspiredParsons to invent the steam turbine were; his love ofattempting to do what others thought impossible, hisknowledge of thermodynamics and the properties ofsteam, and the advent of the electric dynamo. A furtherpopular suggestion is that he was fired by the quest forpure rotary power.

Fig. 6 Neptune Banks Power Station 1902

364 IEE PROCEEDINGS, Vol. 134, Pt. A, No. 4, APRIL 1987

All these suggestions are entirely plausible and I wouldnot disagree with them; my only contribution is tosuggest that he took a circuitous route to develop thesteam turbine.

of high-speed generators. Viewed with hindsight thearrangement looks clumsy but some 40 or moremachines were sold, and the fact that Parsons allowedother manufacturers to use his designs contributed to his

Fig. 7 Relative Dimensions of reciprocating steam engine and steam turbine for 3500 kW output

In the late 1870s while he was working as a premiumapprentice at Sir William Armstrong's Elswick Works,Parsons developed an epicycloidal reciprocating steamengine in which both the cylinders and the crankshaftrotated [13]. By this means each opposed pair of fourpistons, arranged at right angles, were coupled by a solidconnecting rod driving a crank pin. Consequently theinertial forces inherent in a reciprocating engine were bal-anced and the machine ran at a speed of 900 rev/minwhich was suitable for direct coupling to existing designs

departure from Elswick.History is punctuated by questions of 'might have

beens'. If Parsons had not left Elswick and if his rocket-propelled torpedoes had been successful, would he havedeveloped the stream turbine?

I am sure the answer is 'yes'. The clue lies in his note-book [6] entitled 'Gas engines' and unusually the firstpage is dated the 20th October 1881. The first entryreads: 'The defects of all gas engines now in the marketare:

Fig. 8 SY 'Turbinia' alongside RMS 'Mauretania' 1907

IEE PROCEEDINGS, Vol. 134, Pt. A, No. 4, APRIL 1987 365

(i) their great weight and costliness(ii) their want of careful skilled attention and tendency

to go wrong'.

It seems that Parsons had subscribed to the currentthinking that the key to efficiency of heat engines was theachievement of a high top temperature. The upper limitof temperature in the internal combustion engine wasthen about 1900°C compared with under 200°C for thesteam engine using saturated steam. Others of his papersof 1880/1881 deal with petrol engines and internal com-bustion engines generally, but there appears to be nonereferring to steam engines.

October 1881 is an interesting date. He had joinedKitson that year to work on rocket-propelled torpedoes,so why did he choose to consider the gas engine in itsrole as a prime mover? Could it have been because heforesaw the then infant market for distributed electricityfor domestic lighting as developing into one of immensesize requiring prime movers of vastly increased powers tosatisfy a much wider market? In the 'Gas engines' note-book he first reviews the then chancy methods of igni-tion, concluding that an electric sparking plug could bethe solution, before he starts to consider separating thethree stages of compression, combustion and expansion.Many complicated devices are reviewed with sketchy cal-culations, such as a rotating torus filled several times asecond with an explosive gas mixture and water which isexpelled through jets operating on the principle of theHero turbine. Then opposite to page 50 (Fig. 9) there isdrawn over calculations written in ink a pencil sketch ofa turbine wheel driven by air.

On the next page of the notebook there is a calculationof the power of a gas turbine, with a top temperature of2500°F. On the basis of assumed efficiencies of 60% forthe pump and 50% for the motor, he concludes that foran output of 8.4 hp about 7 lbs of coal would be requiredper brake hp per hour.

This background sheds light on the description in thecomplete specification of Patent 6735 of 1884: 'Improve-ments in rotary motors actuated by elastic fluid pressureand applicable also as pumps'. The first two and a halfpages refer to the general category of 'elastic fluids, suchas gas and steam' and include the following description:

'Motors according to my invention are applicable to avariety of purposes, and if such an apparatus be driven, itbecomes a pump, and can be used for actuating a fluidcolumn, or producing pressure in a fluid. Such a fluidpressure producer can be combined with a multiplemotor according to my invention so that the necessarymotive power to drive the motor for any requiredpurpose may be obtained from fuel or combustible gasesof any kind. For this purpose I employ the pressure pro-ducer to force air or combustible gases into a closefurnace of any suitable kind such as used for caloricengines into which furnace there may or may not beintroduced other fuel (liquid or solid). From the furnacethe products of combustion can be led, in a heated state,to the multiple motor, which they will actuate. Conve-niently the pressure producer and multiple motor can bemounted on the same shaft, the former to be driven bythe latter; but I do not confine myself to this arrange-ment of parts.

'The blades should be of material that will withstandhigh temperatures or I may employ water or other fluidto cool the blades. This may be done by providing in thecylinders that carry the blades, channels or passages forthe circulation of cooling fluid, which in the case of therotary cylinder may be supplied through a passage orpassages in the shaft carrying the cylinders'.

It is not until after some 2000 words that Parsonsstates: 'I will assume that steam is the actuating fluidemployed'.

I suggest that there is strong evidence that claim 10;'the use for pumping of two machines of the kind here-inabove described coupled together so that the one con-

t:

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A

Fig. 9 Extract from Parsons's notebook 'Gas engines'

366 IEE PROCEEDINGS, Vol. 134, Pt. A, No. 4, APRIL 1987

stitutes a motor and the other a pump driven by suchmotor as hereinabove described', represents the core ofhis invention incorporating the principle of pressure com-pounding, and that the steam turbine was a special appli-cation more readily achievable in practice.

I referred earlier to historical 'might have beens'.Before setting out on his voyage to the West Indies in1931 Parsons declared that he would use his leisure tothink about the method of casting the primary mirror forthe Mount Palomar telescope and to develop the solu-tion for the gas turbine. Had he not died during thatvoyage, could he have made practical the concept he pos-tulated nearly 50 years earlier?

4 The exploitation of an invention

The story of the development of the 1884 and subsequentParsons Patents is a good illustration of the need for anavailable market to exploit an invention and of the slowand expensive process involved in commercially estab-lishing an innovation.

In 1884 the idea of a turbine was not new. In additionto Hero's turbine of about AD 100 and de Branca'sturbine of 1629, almost 200 British Patents relating toturbines had, by then, been granted. There had beensome limited practical applications such as driving circu-lar saws and separators but Parsons's turbine was thefirst practical one to meet an emerging market andcapable of development to the large ratings that thatmarket would eventually need.

The prototype machine was first exhibited at theInventions Exhibition of May 1885 and it was withremarkable foresight that 'Engineering' [14] reported:

'If the motor ... accomplishes one-half that is ascribedto it by rumour, namely that it will run steadily at manythousand revolutions per minute with an expenditure ofsteam that is not extravagant, it will constitute by far themost noticeable feature in the electric lighting depart-ment of the exhibition and will even rank among theforemost novelties of the entire collection on the ground'.

But it is never an easy task to establish an invention.Parsons expressed the difficulty very well in his Presi-dential Address to the British Association in 1904:

'If the invention, as is often the case, competes with oris intended to supercede some older method, then there isa struggle for existence between the two. The new inven-tion, like a young sapling in a dense forest, struggles togrow up to maturity, but the dense shade of the olderand higher trees robs it of the necessary light. If it couldonly once grow as tall as the rest all would be easy, itwould then get its fair share of light and sunshine. Thus itoften occurs in the history of inventions that the sur-roundings are not favourable when the first attack ismade, and that subsequently it is repeated by differentpersons, and finally under different circumstances it mayeventually succeed and become established'.

The establishment of a new invention against an exist-ing method and entrenched conservatism always involvesan initial outward cash flow before profits can be made.The typical curve is shown in Fig. 10; the greater theinnovation the longer is the timescale and the larger isthe cash outflow. This fact is as true today as it hasalways been in the past.

In addition to these inherent difficulties Parsons hadother serious setbacks, such as the loss of his 1884Patents at a critical stage in development and theproblem of cavitation in Turbinia's propellers. Later, inplacing the order for HMS Viper, the first turbine-driven

destroyer, the Admiralty demanded a guarantee of£100000 (some £4000000 today) that she would attainthe quoted speed.

It is a measure of his indomitable courage that he per-severed to achieve ultimate success. More than once he

Fig. 10 Typical pattern of cashflow in exploiting innovation

appeared to risk his financial all, but his superb convic-tion carried him over each 'big jump into the unknown'.In 1898 when he applied to the Privy Council for a fiveyear extension to his 1884 Patents, he claimed that afterdeducting 7% interest on capital employed in hisbusiness and without charging for his time, he had madea loss of £1107 13 10 (£1107.69). Had he called his book-keeper an accountant and had he not owned his ownbusiness, it is questionable whether he would have beenallowed to carry on for 14 years making such a loss!

Any extremely innovative adventure relies on self faithfor its achievement. Self faith is sharpened by self finan-cing and very few inventors can afford this today.Parsons could well have discarded his steam turbine in1890 or Turbinia in 1895 or 1897; but he fought on. Thatis one of the reasons why we still respect his name.

Since Victorian times our business culture has changedto give more prominence to the dangers of the future andto take a more cautious view of the opportunities itoffers. Although there are still a few people who are pre-pared to wager their money and livelihood on a high-riskventure, most financial backers expect to be comforted bya forecast budget that shows the business to becomeprofitable within two or three years.

We have also become too impatient over timescale.Because of the sophistication of technology, the scale andcost of innovation has increased. Whereas technologyshould have made us better equipped to develop innova-tion more rapidly, the growth of bureaucracy andresponsibility by committee has far outstripped theadvantage. Could we, today, bring to a successfuloutcome within three and a half years such an innovativeadventure as Turbinia? Twice that time would now bethe minimum, and despite the possibly successful applica-tion for a grant from some central organisation, and theassociated time delay, it is doubtful whether private riskcapital would be available to fund the balance over sucha long period.

There are, of course, cheering examples to the contrary,such as Edmund de Rothschild's long and continuingcrusade to establish the straflo water turbine. On the cor-porate scale there are businesses, such as in the phar-maceutical industry, whose future existence depends onpainstaking longterm research to develop new products,and a recent advertisement [15] cites investment of up to£60 million over 12 years to produce one new drug.

There are also encouraging moves to finance new-venture businesses both by financial bodies or consortia,often involving merchant banks, and by tax concessionsto individuals investing a relatively small sum in a newrisk venture. Most of the aided ventures, however, tend

IEE PROCEEDINGS, Vol. 134, Pt. A, No. 4, APRIL 1987 367

to be in the nature of new applications of existing tech-nology. We need to extend the courage and patience ofsuch investors and their potential financial benefits tofund 'big jumps' or quantum leaps in technology that willultimately spawn new industries tomorrow.

5 Conclusion

In 1884 Professor Sir Alfred Ewing observed that the gasengine had all the greater margin for future improvementwhereas the steam engine 'had been improved so far thatlittle increase in its efficiency can be expected and morethan a little is impossible'.

For the generation of electricity in central thermalpower stations and the propulsion of very large ships, thesteam turbine remains predominant. Between 1884 andhis death in 1931, 47 years, Parsons developed singlemachines from a rating of 7.5 to 50000 kW, a factor ofnearly 7000; in the same period electrical generatorsincreased from 200 to 50000 kW, a factor of 250. In thesucceeding 54 years machines have been developed up to1 300000 kW; a factor of only 26!

For naval ships and aeroplanes the gas turbine is para-mount and, if I am correct in my supposition, that is thelater flowering of the original progenitor of the inventionof the compound steam turbine. The reciprocating inter-nal combustion engine has secured the small to mediumpower range in mobile applications and to larger powersin ships, but for static power the electric motor poweredby a central distribution system rules the roost.

I like to think that all this has come about becauseParsons foresaw the need for a prime mover capable ofdevelopment to large power output at high rotationalspeeds to meet the longterm requirement of the infantelectrical supply industry.

It is an example of the catholic nature of engineeringthat in satisfying a perceived need in one field an inven-tion was conceived that had the potential for develop-ment into many other fields.

6 Acknowledgments

I wish to thank very many people for their help in pre-paring this paper. It would be tedious to name them indi-vidually but they are to be found within NEI ParsonsLtd., the North Eastern Electricity Board, the Universityof Dublin, the Science Museum and among other friends.I am also grateful to the Newcomen Society for per-mission to restate some of the contents of my paper 'Theorigins of the steam turbine and the importance of 1884'presented at the Parsons Symposium on the 27thOctober 1984.

7 References

1 'Chambers biographical dictionary 1961' revised 1984, p. 10222 APPLEYARD, R.: 'Charles Parsons: his life and work' (Constable,

1933), p. 293 SMITH, Sir FRANK: 'The first Parsons Memorial Lecture: Sir

Charles Parsons and steam', Trans. North East Coast Inst. Eng.Shipbuild., 1936/37, 53, pp. 31-52

4 HORSLEY, W.D.: 'The 29th Parsons Memorial Lecture: the highspeed generator; eighty years of progress', Trans. North East CoastInst. Eng. Shipbuild., 1964/65,81, pp. 69-92

5 GIBB, CD. : The 12th Parsons Memorial Lecture: Parsons; theman and his work', Proc. Inst. Mech. Eng., 1947,156, pp. 213-218

6 PARSONS, C.A.: Archives PAR 10/1, UK Science Museum library7 PARSONS, C.A.: 'Improvements in steam turbines' British Patent

Application 1120, 1890; 'Improvements in engine governingarrangements' Patent Application 11083, 1890; 'Improvements insteam turbines' Patent Application 10940, 1891

8 PARSONS, C.A.: 'Presidential Address to N.E. branch of Institu-tion of Civil Engineers, November 1895'. UK Science Museumlibrary

9 HANNAH, LESLIE: 'Electricity before nationalisation' (MacmillanPress, 1979), p. 17

10 Letter from George Baden Powell, The Times, 29th June 189711 The Times, 28th June 189712 PARSONS, C.A.: 'Flying engines', Letter to Nature, 1896, 54 pp.

148-14913 'Exhibits at the Inventions Exhibition: Parsons' high speed engine',

Engineering, 1885,39, p. 46014 'Exhibits at the Inventions Exhibition: Parsons' motor and

dynamo', Engineering, 1885, 39, pp. 460-46115 The Times, 1st October 1985, p. 7

Book review

Mathematical methods in electrical engineeringThomas B.A. SeniorCambridge University Press, 1986,272 pp., £25.00ISBN 0521306612

This is an undergraduate textbook based on a course inmathematical methods which, for over a decade, has beenobligatory for all students in electrical and computerengineering at the University of Michigan.

The material covered is the usual stuff, following onmore-or-less directly from school (in the UK) or JuniorCollege (in the USA) but, reading through the book, oneis immediately impressed with the clarity of the presen-tation and with the pedagogical gifts of its author. Thestudent is led gently through the development with ele-gantly arranged pauses for detailed explanation wherethe author, from his classroom experience, knows fullwell there is going to be difficulty. Each section of text isfollowed by some well chosen problems on which thestudent can test his newly aquired competence. In fact,the writing and structuring of the book are both so good

that it becomes quite feasible for the better student toconsider working through the course without calling onmuch in the way of teacher-guidance at all.

The topics, in order, are complex numbers, Laplacetransforms, linear systems, Fourier series, functions of acomplex variable, Fourier transforms and the relationbetween the various types of integral transform. This isindeed the basic mathematics of electrical engineering,but one feels that many physics students as well will findthis book of value. In this connection, one finds the onlyreal criticism, namely that several times in the course ofthe development one comes within a hair's breadth of thetheory of causal functions and of the consequent theoryof dispersion. If the author had not, in each case, so inex-plicably held back, this book would be without doubt thebest undergraduate text on this area of mathematics. Asit is, it is very good indeed and can be whole-heartedlyrecommended.

G.W. CHANTRY

5312A

368 1EE PROCEEDINGS, Vol. 134, Pt. A, No. 4, APRIL 1987