WESTERN CENTRE: CHAIRMAN'S ADDRESSBy J. B. J. HIGHAM, Member.*

"AIDS TO TECHNICAL TEACHING"

(ABSTRACT of Address delivered at CARDIFF, 1st October, 1945.)

In the first place I must express my deep sense of appreciationof the honour accorded me on being elected Chairman of thisCentre; secondly, I am very conscious of the high standard ofchairmanship shown by previous holders, a standard which it isnot easy to attain. I shall do my utmost to uphold the dignityof the office, and I know that I can depend upon the valuableassistance of the officers and members of your Committee incarrying out the duties involved.

Towards the end of my predecessor's term of office cameVictory in Europe, and the final collapse of Japan, which fol-lowed quickly the great scientific achievement of the release ofatomic energy on a scale sufficient to annihilate a city of the sizeof Cardiff. Even the scientists engaged directly in the researcheswhich have produced this staggering new weapon of war cannotyet say with any certainty to what it may lead, but they will intime surely discover a way of controlling the rate at which theatomic energy is released. In view of this epoch-making achieve-ment, what I had to say in my Address seemed to sink intoinsignificance, but I decided, nevertheless, to proceed.

I had planned what follows some time ago, and in view ofthe need to discuss in some detail the subject of "training ofcraftsmen" I have omitted, except for a brief reference, touchingupon it. I am hoping that this Centre will have an opportunityto discuss this matter at an informal meeting some time duringthe session. The problem of craft training in an area such as iscovered by the Western Centre is very different from that in thelarge electrical manufacturing districts, and one which willrequire careful thought.

I shall conclude my Address with a series of simple experimentsshowing certain electrical circuit characteristics. This willillustrate what powerful means are available to-day for demon-strating fundamentals, as compared with those of only a coupleof decades ago. The experiments, I hope, will be of interest tothe older members as well as instructive to the students, whomay have had little opportunity of studying the circuit conditionsfor electrical transients.

The basic purpose of my Address is to bring to your noticesome matters relating to technical education. As in recent yearswe have had several Reports dealing very fully with the trainingof electrical engineers and craftsmen, and as in addition severalChairmen of other Centres have dealt with certain aspects of thesubject, I thought it advisable to avoid criticism of, or enlargingupon, the proposals put forward; instead, I think a short dis-course on some matters of a domestic character will not beout of place. It contains some criticism and, I hope, some con-structive suggestions. I hope, too, that the younger memberswill be able to appreciate what tremendous advantages they haveover those of us who studied the A.B.C. of our science severaldecades ago; and at the same time I may remind the oldermembers of the great increase in knowledge which the present-day student has to absorb in order to pass the present-day formof examination, so much so that the time available for thestudent to think more for himself and cultivate a critical judgment

• School of Mines and Technology, Treforest, Glamorgan.

is almost non-existent—more's the pity. In this way I shall, toa certain extent, follow the lines of several Past-Chairmen inmaking some comparisons between the present and the past.In order to be concise I have confined my remarks to six maintopics.

(1) TECHNICAL COLLEGE LABORATORIES(1.1) Arrangement and Equipment

Twenty-five years ago relatively few Technical Colleges, evenin the larger towns, were equipped with any but the most ele-mentary type of apparatus, and in those relatively well equippedthe engineering laboratory was often unsuitably situated, withno room for expansion. In some cases large sums were spenton schemes too elaborate in the first place. In contrast, anumber of the larger college laboratories were well equipped.

The equipment of engineering laboratories should be gradual,and room should be left for development, best decided by ex-perience, enabling new types of machines and apparatus to beinstalled. The sizes of machines have often been unnecessarilylarge, leading to a reluctance to scrap old or obsolescent machines.

The provision of a small crane or wheeled gantry for movingthe heavier apparatus is well worth considering, as it enablesbetter or new arrangement of apparatus to be quickly made;servicing and repairs are also more rapidly accomplished.

The fixing of machines on massive foundations, or on in-linebed-plates, with large grouped or separate switchboards shouldbe avoided. The present tendency to place machines under testtables is wrong; free and easy inspection should be the aim.

Terminal arrangements require careful thought, and in thecase of motor-generators and the like, one machine should beslung suitably to enable torque to be measured. Whereverpossible, fixed electrical speed indicators should be provided.

The supply of power should be as flexible as possible, andample floor and wall ducting should be provided, supplementedby overhead supply, with flexible coupling cables, so much usedin modern machine shops. Additional cable runs, formingring mains, broken by suitable sockets and plugs, facilitate theinterconnection of machines and apparatus, and minimize thelengths of flexible test cable. Laboratory walls should beprovided with means for readily fixing switches, apparatus andspecial instruments.

Portable test tables are advisable for nearly all advanced workin the testing of machines and transformers. Many can be easilydesigned so that the top can be kept clear when not in use fortesting, and the laboratory should be kept as free as possiblefrom large fixed benches.

Instruments and much of the bench test apparatus should bekept in a proper store room. This eliminates waste of space inthe laboratory and saves time in setting up experiments.

Certain machines and apparatus may be permanently con-nected, but the majority should be connected, when required forexperiments, by the students.

Proper provision should be made for the testing of instruments,quickly and easily, on a permanently wired test bench. Students

[99]

!00 HIGHAM: WESTERN CENTRE: CHAIRMAN'S ADDRESS

often place too great a faith in instruments, and when resultsdo not agree with those expected they often doubt the truth ofstatements made by the teacher.

There is need for education authorities to recognize thenecessity of acquiring more new apparatus for the engineeringlaboratories in order to keep pace with progress. The engineer-ing laboratory should not be looked upon as equipped to lastfor several generations without modification or addition.

The use of engineering laboratories should not be restricted tothose training as technicians or preparing fora professionalcareer. Craftsmen should have some knowledge of the tech-nicians' work, and technicians should know something of thecraft.

(1.2) Laboratories in Small Evening InstitutesI think it is the common experience of the Advanced Technical

Colleges that the students who come from the PreliminaryInstitute, and who have usually pursued evening courses, havenot had much opportunity for individual laboratory work. Thisusually means that the best use is not made of the facilitiesavailable in the advanced courses. The early experimental workneed not be elaborate; in fact it should not be, but should bedesigned to introduce the student to the correct use of instru-ments and the neat tabulation of observations, and, even moreimportant, the presentation of a concise statement as to theobject of the experiment in the first place, and later, some com-ments on the results. The proper purpose of graphs should bestressed; too often it is found that students think that a graph isa subtle bit of "cooking."

I have here a suggestion to enable the practical laboratorywork to be more readily available to small Institutes scatteredover a wide area, such as the County of Glamorgan. The costof providing machines and apparatus for each and all may be soprohibitive that it is not provided, and my suggestion is that anumber of suitable motor vehicles be constructed, or modified,and equipped with certain machines and apparatus for electricaland mechanical laboratory work; general science experimentscould also be dealt with at the same time. I would suggest thatthe vehicle should be provided with simple tackle to enablewheeled units to be shipped and unshipped readily so that theapparatus could be taken into the Institute for use. The vehiclecould carry a.c. and d.c. generators of suitable size to supplypower for experiments where power was not available, althoughthis condition is not likely to exist in many Institutes.

It would be necessary to arrange a proper programme ofperiods for laboratory work at the various Institutes, correctlyrelated to lecture progress, but that should be relatively easy nowthat nearly all courses are working to a common syllabus ofpreliminary studies leading to the various National Certificates.In these courses it is just as well to have a more or less standardsyllabus to work to, and a common series of laboratory experi-ments would be an advantage. Lack of laboratory facilities hasin the past made lecture table demonstrations a necessity, but,although I believe it is an advantage to be able to demonstrateto a class at the lecture table, it cannot take the place of actuallaboratory work, where the student learns to do things for him-self. Much more time could be devoted to experimental workthan has been done in the past, and with great benefit.

(2) THE SUBJECT OF ENGLISHThere is another matter which needs attention at an earlier

stage than is often the case, and that is the need to train studentsto express their thoughts in plain and simple English. It isillogical to allow students to progress to the Ordinary NationalCertificate, and in some cases to the Higher National Certificate,before they have satisfied The Institution in the subject of

English. This matter is now receiving the close attention of allconcerned. It is becoming increasingly obvious that the averageand below-average student is unable satisfactorily to answerquestions of a "descriptive" type. In a few instances this isbecause the student has no clear idea of the subject, but moreoften it is due to the lack of command of simple language. Inview of the enormous amount of literature on engineering sub-jects now available, the relatively small amount of individualreading that is done by the majority of students is surprising.There can be no doubt that some means can be found to improvethe somewhat tedious nature of the usual English lesson; and thesooner the better, for many students do not benefit to the extentthey could from technical instruction, owing to their shortcomingsin the knowledge of their native tongue. It is also surprisingto find that students who have left the primary school at between13 and 14 years of age during recent years are not so well equippedin the matter of English as some of the older people who left atthe age of 9 or 10 some 50 years ago. Extremely poor hand-writing is also very evident.

(3) COLLEGE ENGINEERING SOCIETIESEvery Technical College of any size has its Engineering

Society, and despite the difficulty of being entirely self-supportingin the provision of suitable lectures or talks, it is advisable tomake every effort to be so. I am afraid that many suffer fromthe fact that not enough support is given by the majority of thestudents, and it needs the continual attention of heads of depart-ments and staffs to keep the Society in a live condition. I thinkthat one reason is that there are so many modern distractions,and another, that many students really have so little time foranything else but their studies. Whether the lectures are heldinside the usual times of attendance at classes, or after the day'swork, is largely a matter for the principal or head of department,but I think that voluntary attendance after class hours is likelyto be best in the long run.

These Societies provide a wonderful opportunity for studentsto learn how to conduct a meeting properly, to gain confidencein expressing themselves in public without being self-conscious,and to argue and discuss matters in an orderly way. Thestudents who do prepare and give papers are those who benefitmost. They are usually of the type who have some specialinterest, often in subjects outside the course curriculum, and suchinterests should be fostered. It is certainly not essential thatthe lectures should all be of an engineering character; in factsome lectures should be of wider scope and several of theseshould be included in the session's activities.

Unfortunately, the Engineering Society does not give all itsmembers equal benefit; the officers and committee memberscertainly benefit considerably more than the others, and to im-prove on this state of affairs, if only slightly, I would suggestthat the students in each year of a course be invited to send onestudent to each committee meeting. These members should beentitled to take part in any discussion, but not entitled to vote.By this means a greater interest in the activities would be fostered.

(4) SPECIALISTS' LECTURES FOR ADVANCED COURSESThe time has come when some consideration should be given

to the amplification of certain lecture work by the provision ofspecialists' lectures. In the past these have been few and farbetween in most colleges, and they could very well form a regularfeature. These lectures should, I suggest, be given mainly byengineering specialists from local manufacturing firms if possible,but the larger associated companies should also be invited tocontribute lectures. To quote one example: in most advancedelectrical engineering courses the subject of Fault Protection is

fflGHAM: WESTERN CENTRE: CHAIRMAN'S ADDRESS 101

included, and Symmetrical Phase Sequence Components will betouched upon; following this, a specialist who was in closetouch with the proved and practical means of fault protectioncould give a short review of modern systems. He would knowthat his audience had some knowledge of the underlying prin-ciples, and he would be far more capable of dealing with thepractical applications than anyone else. Specialists' lecturesgiven to a restricted class of students would be more useful thansuch lectures delivered to the Engineering Society, where possiblyonly ten per cent of the audience would be capable of absorbingthe subject-matter.

The senior students should be given the opportunity ofmaking some concise notes on the lecture, and possibly two ofthem could be induced to prepare a summary and present it ina very simple form to the Engineering Society; the other seniorstudents would be in a position to ask questions and discuss thepaper and hence give a lead to the junior students. I am suremany of the larger firms would be only too willing to co-operatein this matter, and from my experience there has been no tendencyfor the lecturer to advertise his firm's wares.

These lectures should not be lengthy, they should be of aboutone hour in duration, and ample time should be allowed for aninformal discussion. In the larger industrial areas a series ofsuch lectures would be fairly easily arranged, but once theground had been broken in the smaller and more scattered areasmany of the difficulties would soon disappear.

(5) FILMS AND LECTURE DEMONSTRATIONS(5.1) Films

The war seriously affected the availability of technical films,and it is to be hoped that, when conditions are more normal,more use will be made of the cinematograph. It should not beimagined that the use of films can replace the formal lecturework, but they can be used to amplify lectures to great advantage,and certain films might well be produced to show experimentalwork carried out in the many large research laboratories of theworld. Many excellent films were available before the war, butit is to be hoped that a greater variety will be produced and thatmuch greater care will be taken in their production than in thatof some of the pre-war films. The producers will have to bemen who know exactly what is required and who will not tryto introduce the topical ideas of the cinema, as has often beendone; for example, mimic diagrams have been presented in sucha manner that they approach the cartoon in character; foundryscenes have lost definition and clarity by printing on a redbase.

The use of films should be a great help in courses for craftsmenand will undoubtedly be introduced as a regular feature, ratherthan for special occasion only.

There can be no doubt at all that the easiest way to the mindis through the eye, and that is one reason why the teacher whocan sketch freely and easily in support of his lecture work getshis lectures over to good effect. The student's eye also seesextraneous things, and, to avoid distractions, a teacher mustavoid mannerisms as far as is humanly possible; for the samereason, technical films should be very carefully produced.

For certain advanced work special films would be of great helpin the study of the operation of complicated mechanisms or cir-cuits. An example of the latter would be the operation of pro-tective relays under fault conditions and the testing of such relaysto ensure operation.

(5.2) Lecture DemonstrationsOnly under exceptional circumstances should a lecture demon-

stration be used as an alternative to laboratory work; its proper

function is to amplify lecture work; it needs much care andthought in preparation. Unfortunately there are many EveningInstitutes and Technical Colleges that are but poorly equippedwith suitable lecture theatres for demonstration and manythat are without suitable apparatus, but, now the war is over,more apparatus will become available and much more atten-tion will undoubtedly be given to the provision of demonstrationapparatus.

In recent years, electronic devices have developed rapidly andare becoming of increasing importance in nearly all branches ofelectrical engineering, and we shall see revolutionary changes asa result of their application. One particular electronic device,which should soon be available for use in practically all Institutesand Colleges, is the cathode-ray oscillograph. The very widerange of uses to which this can be put does not permit anylengthy reference in my Address, and for that matter mostteachers are familiar with it and it is my intention to demonstrateits use. I believe that the older members will agree that here wehave an instrument which is superb in the field of demonstration;they will recollect how rare it was for any but the favoured fewto see an oscillograph in operation.

(5.3) A Simple Device for use in conjunction with the Cathode-Ray Oscillograph, whereby many Electrical Transients may beshown without the Use of Elaborate and Expensive ApparatusThe usual form of oscillograph proper is restricted in applica-

tion to the showing of steady-state cyclic variations. Normally,the transient conditions have to be photographically recorded,and this usually means costly oscillographs and cameras, andconsiderable skill in operation is required. There is seldom timeenough to make use of the oscillograph purely for the demon-stration of transients, and it is with a view to enabling certaintransient conditions to be shown visually that I have devised avery simple piece of apparatus to be used in conjunction with thecathode-ray oscillograph. I am giving a simple diagrammaticsketch of the device (see Figure), and a few brief notes on its useas other teachers may find it useful.

[At this point, Mr. Higham used his device, in conjunctionwith a double-beam cathode-ray oscillograph, to demonstrate theelectrical transients summarized below. ]

(5.3.1) Growth and decay of current in a highly inductive circuit.Variation of time-constant.

(a) D.C. voltage suddenly applied.(6) D.C. voltage suddenly switched off, and discharge resistor

placed in circuit.

(5.3.2) Oscillatory and non-oscillatory condition in a circuit withresistance, inductance and capacitance in series; capacitance with noinitial charge.

(a) D.C. voltage suddenly applied.(b) D.C. voltage suddenly switched off.(c) Change of natural frequency of circuit; damping of oscil-

lations by adding resistance until non-oscillatory condition isobtained.

id) Variation of voltage across capacitance during (a) and (6).

(5.3.3) Transients with alternating voltage applied:(a) to highly inductive circuit—at instant of maximum voltage

and at instant of zero voltage. Symmetrical and asymmetricaltransient current. Effect of resistance in damping.

(b) to non-inductive resistance—symmetrical steady state,independent of instant at which voltage is applied.

(c) to series resistance, inductive and capacitive circuit, inwhich the natural frequency is equal to the frequency of the

102 HIGHAM: WESTERN CENTRE: CHAIRMAN'S ADDRESS

Fig. 1.—Interrupter connected for a.c. transients.

1 -Interrupter.2— Shafts, geared positively at suitable

ratio.3-Alternator.4, 5—Slip rings.

6—Discharge resistor.7—Inductor.8—-Resistor.9—Connections to double-beam cathode-

ray oscillograph.A, B, C, D—Brushes, mounted on common rocker.

For most a.c. transients 1 revolution of interrupter is equivalent to 5 cycles, com-ponents 7 and 8 being connected for 4i cycles and disconnected for half a cycle fordischarge through 6. Brushes A and B are of slightly greater spacing than theinterrupter gap.

For most d.c. transients, slip-ring 4 is replaced by one giving slightly more than180° contact and the interrupter is driven at a suitable speed, a battery replacing thealternator. Brushes A and C have approximately ISO" spacing; brush C is connectedto the discharge resistor.

applied voltage, and 2nfis large compared with R/2L.

(5.3.4) (a) current-chopping; restriking voltage.(6) Resistance switching.Illustrating a class of switching high-voltage transient caused

by pre-zero current suppression in inductive circuits, and limita-tion by resistance switching.

(6) RESEARCH IN TECHNICAL COLLEGESThe Second Report on Education and Training for Engineers*

deals in one Section specifically with Research and DevelopmentWork at Technical Colleges,! and especially mentions thatRegional Technical Colleges should be encouraged and assisted

• Journal I.F.E., 1945, 92, Part I, p. 56. t Ibid., Section 4.4.

to carry out a certain amount of engineering research and de-velopment in close collaboration with local industry. I agreethat this would be the ideal arrangement, but I wish I couldthink it would be as easy to realize as to outline. The collegestaff would have to be increased in order to reduce teachinghours, and, even so, much of the out-of-class routine, whichoccupies more time than some people realize, would remain.Even if the Education Authority could be persuaded to appointmore teachers in order to develop the research side, it is doubtfulwhether the profession could attract suitable men from industry,for that is surely the best recruiting ground. I am afraid that,owing to administrative problems, the ultimate arrangementwould be for one member of the staff to be engaged entirelyupon the research, the others carrying on with the routine teach-ing duties; this is just what is not wanted.

Another difficulty would be found in the lack of suitablelaboratory space in most colleges; there is hardly enough roomto carry out the regular laboratory work for normal classes inmany cases, and research work, however simple in character,would require apparatus and instruments to be more or less tiedup—for research cannot be attempted in a piecemeal fashion.The research and development, too, would probably be of spas-modic occurrence and require immediate attention over a periodof several days, or even weeks, so that the teaching would bemore or less delegated, or somewhat neglected.

I am mentioning a few of the problems which will requireclose attention, and, whilst I have my own ideas as to how someof the difficulties may be overcome, I am sure that the properattack is to convince the Education Authorities that researchand development work in Technical Colleges is a vital necessity.Then some recognized and established method must be found topermit money to be spent, within limits, immediately as the needarises; at present, estimates are in most cases passed annually,and any further spending is limited to a few shillings from pettycash.

Some of the difficulties of space and equipment will be con-siderably reduced, if not eliminated, if my suggestions regardinglaboratories and their equipment are carried out in a generousmanner.

Finally, in Colleges where it is possible to carry out researchand development work, provision should be made for advancedstudents to participate actively in such work, or at least to be keptin touch with it and encouraged to offer their own ideas. Workof this sort should not be "secret," and any attempt to make itso cannot be too strongly condemned. It can and should beused as a very powerful aid to teaching.