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  Some recent books  (continued) currents (either alternating  or  direct)  can be  fed  to a  polyphase rotor winding.If the latter  is  a  2-phase arrangement,  for example,  the  values  of  direct current  in the two windings can be varied so as  to  producean artificial angle of Jag or lead of rotor flux,as  in a  loaded synchronous machine.  If  low-frequency alternating current  is fed  to  the rotor, the machine becomes  a  variable-speedsynchronous motor  or  generator.The book contains  a  theoretical treatmentfor this type  of  machine which  is  likely  to interest  the  specialist. Although  it is excellently produced,  it is  very expensive,as  it  contains only 75 pages. E.  R.  LAITHWA1TE North  of  the Border B.  R.  MYERS Vantage  Press, 1963.  214  pp. 3.95 In 1959  the  author, then  an  English immi-grant  to the  United States, accepted  an invitation  to a new  chair  of  electricalengineering  at a  Canadian university. Lessthan two years after taking  it  up, he decided,because  a  variety  of  conditions were  not  to his liking,  to  return.The first third  of  this book is  a  treatment,quite superficial,  of  life  in  Canada  as it appeared  to  him.  The  remaining two-thirdsreviews Canadian engineering education.The stated purposes  of  the  book  are to illuminate  and  constructively criticise  the Canadian scene and  to  alert the prospectiveimmigrant  to  (as the author rather curiouslyputs  it)  certain matters  on  which  he  wouldotherwise have  no  reason  to  ponder.There  is no  doubt that,  to  meet  the  fore-going specification,  a  work should  be, above  all,  accurate  and  objective;  at the same time there would  be  little point  in publishing unless  it  met  certain minimumstandards  of  literary merit. North  of  the Border is  deficient  in all  these qualities.It  is  intensely subjective;  it  contains suspectgeneralisations, inferences offered  as  factsand  a  number  of  inaccuracies.  In  additionto these deficiencies,  the  whole tone  of  the book  is  gratuitously denigrating  of a country  to  which  a  certain minimum  of guest-to-host esteem was due. The reader looks  in  vain  for  any  serious pronounce-ment  by the  author  on  what  he  wishedto  contribute,  a  purpose that might  be generally considered  as an  integral part  of an educator s personality. F.  GALL Taschenbuch  der  Nachrichten-verarbcitung K.  STEINBUCH  Editor) Springer-Verlag,  Berlin,  1962. 1521  pp. DM98 This  is a  co-operative work  on  data  and information processing written  by 47 specialists from German industry  and edu- cation.  The  declared object  of  the  work  is to provide  the  engineer, mathematician,physicist  and  executive with  a  view  of  the subject  as  a  whole. This  it  certainly does.In 1500 pages there  is a  vast amount  of information, ranging over digital  and ana- logue computers practical data-processing290machines, tape  and  other automaticmethods  of  control  of  machine tools,letter sorting, automatic methods  of  trafficcontrol and Boolean algebra. As  a  referencebook in the German language  it  is doubtlessinvaluable;  it  suffers,  of  course, from  the same defects  of  overcompression  of material  as  any  other handbook.  A  trans-lation into English would  not  serve  a useful purpose  in  view  of  the many existingworks  on the  subject. G.  s.  BROSAN Matrices, their meaning and manipulation * W.  G.  BICKLEY  and  R. S. H. G.  THOMPSON English  Universities  Press, 1964. 164  pp.21s. This book  is  based  on  lectures given  to third-year  and  postgraduate engineeringstudents  of  Imperial College.  The  authorsaim  to  familiarise  the  reader with  the lan- guage  of  matrixes  and to  provide infor-mation  on the  necessary techniques  for the arithmetical solution  of  problems whichdepend  on  linear equations.The text opens with  a  selection  of problems,  the  mathematical formulationof which leads  to  sets  of  linear algebraic  or differential equations  in  which matrix alge-bra  can be  used effectively. Matrix algebrais then developed  and  special matrixes  are considered, followed  by  applications  of matrix products.  The  solutions  of  systemsof linear equations  are  next considered,as well  as  various concepts  and  methodsconcerning these solutions, including pivotalcondensation, ill-conditioned equations,inversion  of  matrixes,  the  improvement  of an approximate inverse,  and  iterative  pro- cesses.  The  later chapters  are  concernedwith eigenvalues  and  eigenvectors  and their properties, eigenvector matrixes,  and the determination  of  eigenvectors and  of  thecharacteristic equation.Many exercises  for  solution together withhints  and  answers  are  provided throughoutthe book, some  of the  examples beingintended  to  indicate extensions  and  appli-cations  of  the  theory.While  the  work  is  intended  to  provide  an introduction  to  matrixes  and to  some  of their applications, qualified engineers  and advanced students  who  have some know-ledge  of  the subject will find this informative treatment of the material of considerable interest  and  value.  F. H. JACKSON Elements  of  plasma physics S. GARTENHAUS Holt, Rinehart   Winston, London, 1964.198  pp.  £3 16s. In recent years, appreciation  of  the  poten-tial uses  of  plasmas  in  practical deviceshas resulted  in the  publication  of a large number  of  research papers  on the many aspects  of  the  subject.  Prof.  Garten-haus s book  is  written primarily  for the research-minded student  who  wishes  to proceed from  a  degree-level knowledge  of plasmas  to  the  deeper insight gained fromarticles  on  current research.  The  subject-matter  of  the book  is  limited mainly  to the description  of a  plasma given  by the Boltzmann-Vlasov equation. This equationis essentially  the  bridge between  the  micro-scopic picture  of a  plasma  in  terms  of particle motions)  and the  macroscopicequations  of  plasma behaviour.After introductory chapters outliningstandard electromagnetic theory  and charged-particle dynamics  in  electric  and magnetic fields,  the  Boltzmann-Vlasovequation  is  derived,  and  practical applica-tions  of  the  equation  are  demonstrated  by using  it  to obtain the macroscopic equationsgoverning magnetoplasmadynamic flow andplasma oscillations.The book is well produced, and the authorhas obviously made considerable efforts  to help  the  reader gain  a  lucid  and  criticalpicture  of  current work  in  this field.  To  thisend, much recent work  is  included,  and selected reading matter  and  problems  are provided  at  the end  of  each chapter.While  the  text  is  hardly  of  generalinterest, research students  and  workers  in plasma physics will find  it  an  excellent  aid in appreciating this important,  but  oftenpoorly understood, fundamental descrip-tion  ol a  plasma.  i.  R.  MCNAB Brains, machines  and  mathematics M.  A.  ARBIB McGraw-Hill,  1964. 152 pp.  54s. The title  of  this book  of 150  pagesdoes  not do  justice  to its  contents.  It is really about  the  theoretical aspects  of information technology  as it has  evolvedsince  the  war.  It  concerns  the  quest  for the ultimate possibilities  of  machines,machines that  can  store information  and can change their procedures accordinglywith past successes  or  failures.  In  particular,the digital computer  and its  derivatives,  the  finite automata ,  are  explained  and ana- logies  to the  more elementary aspects  of animal neurons demonstrated.  The use  of value-words like superior and  intelligent ,and  of  metaphors,  too,  when comparingcomputers  and  brains, need  not  deter  the sensitive reader;  the  technical material  is presented clearly, precisely  and  widely.The writer  is  well qualified  to  write  on the subject.  c.  CHERRY Vector fields W B BOAST Harper and  Row,  1964.  620  pp.  £3  19s. The introduction  of  vector methods  at an early stage  in a  degree course  is to be encouraged,  but it is  clear that certaindifficulties arise  if one  insists  on  doingeverything  the  vector  way,  as  Boast does.For example  the  proof  of the  formula S>Hdl I  involves  a  double line integralwhose value is  477,  but  this  is  stated without proof.  This  is  surely less satisfactory thanthe simple  but in  principle rigorous) proofof  the  above equation which  can be  givenwith the help  of  the magnetic-shell concept.The dust cover claims that vector analysisis given full treatment in an  appendix,but this  is  difficult  to  accept when there  is no discussion  of  the  difficult concepts  of line, surface,  and  volume integrals.Most  of  the  book  is  devoted  to  staticfields. Maxwell s equations,  the  wave Electronics and Power August 1964  equation  and  retarded potentials  are  givenonly  11  pages. Retarded potentials  are introduced with  no  justification,  and it is never even stated,  let  alone proved, thatA good deal  of  attention  is  paid  to numerical methods  in  solving static-fieldproblems. Computer flow charts  are  givenfor  a few  problems,  and the  results  are discussed. Flux plotting  is  also discussedin some detail,  and a  number  of  examplesare given to illustrate  its  application. Theselast  two  topics occupy  100  pages  and a special feature  of  the book.There are plenty  of  problems  at  the endof each chapter,  but no  solutions.  On the whole,  the  problems  are  very conservativein character  and do  little  to  stimulate  the students imagination.The book will probably  be  found usefulfor occasional reference  by  undergraduatestudents; many aspects in static-field theoryare worked  out in  great detail.  It is,  how-ever, generally  too  slow-moving  and too uneven  in  level  to be  recommended  as an undergraduate textbook.  A.  L.  CULLEN Magneto-hydrodynamic generation  of electrical power* R.  A.  COOMBE  Editor) Chapman  and  Hall,  1964.  207 pp.  30s. M.H.D. generation  has,  understandably,attracted  the  attention  of  research teamsin many countries,  but  unfortunatelyresults can be obtained only by the expendi-ture  of  large sums, sponsored  at  nationallevels.It  is  therefore refreshing that  the  editorof this book took  the  initiative  to  compilea series  of  lectures to cover very adequatelyfor engineers the principles, characteristics,and possibilities  of  an application  of  one ofFaraday s discoveries. These lectures, givenin 1962, form the basis  of  the present text,which  is  quite  up to  date  for the  engineerwho requires good background informationon the subject.Tn view  of the  wide range  of  scientificprinciples involved with this form  of generation, including  the  seeding  of an ionising  gas, the use of  superconductingmaterials, temperatures ranging  up to 4000°C  etc., the  group  of  scientists  who contributed  to  this book provide  an excellent combination  for  dealing with  the subject.  An  adequate list  of  references  is included. F.  BARRELL The  art of  simulation K D TOCHER English Universities Press,  1964. 184 pp.  25s. Until about  15  years  ago,  statisticians—and indeed scientists generally—usuallytried  to  obtain  an  analytical solution  to any problem that seemed likely  to  have one.  With  the  coming  of  electronic digitalcomputers,  an  easily calculable solutionbecame less important.  One of the new possibilities  was  statistical simulation,  i.e. the numerical computation of many specificsolutions, randomised  as far as  possible,in order  to  discover their distribution. Electronics and Power August 1964 It would  be  wrong  to  suppose, however,that  a  naive approach plus plentiful com-puting capacity solves  all  problems.  We usually need  to  know  the  probability  of highly improbable occurrences. Estimatingit  by  simple simulation  is  like trying  the measure  the  failure rate  of a  very reliablecomponent: simple problems could takeyears  of  computing.Practical simulation depends on choosingthe most efficient methods  of  sampling andestimation.  The  general principle  is to construct  a  random variate  or set of variates) with  the  minimum variance,  by elimination  of any  known systematiceffects; this  is the  central topic  of the book.The theoretical basis  of the  methods  is admirably stated;  so is  their realisation  as flow diagrams  for  computation, examplesof both queuing and cyclic problems beinggiven. There is also  a  good critical summaryof methods  of  generating random  and pseudorandom numbers.The book  is  heartily recommended,  not only  to  practitioners  of  the art,  but to  anyengineer with  an  interest  in  statistical methods. K. w.  CATTERMOLE [Not held in the Institution library.]Boolean algebra and its application H G FLEGG Blackie,  1964. 261  pp.  £2  10s. Ordinary algebra deals with generalisedarithmetic; Boolean algebra deals withclasses or groups within  a  larger population.It  was  first introduced  by  Prof.  Boole  in 1847 under  the  title  of  The mathematicalanalysis  of  logic ,  tn  modern electricalterms  it  might  be  called  the  algebra  of switching,  and in  recent years Booleanalgebra  has  played  an  increasingly impor-tant part  in  the development  of  circuits  for computing, communication and control.The book under review has been writtenwith these engineering applications in mind.The author  has  attempted  to  provide  an elementary account  of the  essential prin-ciples, assuming  no  previous specialisedknowledge.  He  starts with  a  chapter  on binary numbers before proceeding  to the basic operations  of the  algebra. Havingestablished  the  principles,  he  applies themto switching circuits. The first half of the textis well within the capabilities  of  any intelli-gent engineer. Indeed, some  of the  earliermaterial could well  be  used  in  arithmeticcourses  in  schools. There  are  numeroushelpful diagrams and worked examples,  as well  as  graded exercises  at the end of the chapters.  The  second half  of the  bookinvolves some  of  the concepts  of  electrical-network theory  and  matrix algebra. Thiswork  is to be  welcomed  and can be thoroughly recommended as  a  readable andauthoritative introduction  to  Boolean alge- bra for engineers. M. R.  GAVIN  ooks received Nuclear electronics. Paris, OECD, Euro-pean Nuclear Energy Agency,  1964. 860 pp.  £3 3s.  (Proceedings  of the  inter-national symposium  on  nuclear electronics,held  in  Paris, 25th-27th November 1963.Papers  in  French  and  English. Frenchpapers have summaries  in  English)Directory  of  opportunities  for  qualified men,1964-65 edited  by C.  Labovitch. Corn-market Press, 1964. 158  pp.  12s.  6d. Midlands Electricity oard  t use ripple control The Midlands Electricity Board have recentlyordered ripple-control equipment, which  is to be installed  at  the 275/66kV Grid supplypoint  at  Feckenham, Worcestershire.  The initial installation will give  a  control signalover several hundred square miles  of the surrounding area  and is a  pilot scheme  to enable theoretical  and  practical studies  of this method  of  control  to be  investigated,when associated with  an  extensive  66 kV distribution network.  The  results  of  thesestudies will be used  as a  basis  for  consider-ing  the  application  of  similar schemes  to the 132kV system,  so  that coveragecan  be  obtained  of  larger areas  and loads with  the  minimum number  of in- jection points.Basically, ripple control comprises  a transmitter  at an  appropriate point  in the electricity network  and  receivers that  are fitted to individual items  of  equipmentthroughout  the  supply system.  The  trans-mitter injects signals into the network, andthese pass through the system. Each receiveris  set to act on a  particular signal.  A  largenumber  of  separate signals can  be  injectedinto  the  mains network,  and  these  can be used for such different purposes as switchingon  and off  storage heaters, water heaters,street lightingand individual industrial loads.This gives great flexibility  in  control:  it allows engineers  to  continue  to  maintainoff-peak tariffs right  up to the  time thatnormal demand increases, thus giving  the consumer  a  better service and enabling  the board  to  sell more electricity.The Feckenham scheme, which  is the first of  its  kind  and  size  in  Britain, willcomprise audio-frequency injection  at 300 c/s, using parallel injection into  the 66 kV  system.  At the  present time,  the system has  a  maximum load  of  230  MW.For controlling off-peak loads, relays willbe installed  in  place  of  spring reserve timeswitches on consumers premises and, for testpurposes, on individual pieces of equipment.It  is  intended that experiments will  be carried  out on  the control  of  off-peak loadsand  in  analysing the load characteristics  of various domestic appliances. This  can be done using the  flexibility  of operation whichthe telecontrol system provides.The equipment  is  capable  of  sendingout  254  different command signals,  and a number  of  these have high-security codesso that they can be used  for  system switch-ing, such  as the  control  of  transformertap changers  for  load reduction. 291
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