44 H A Y A N D M O W D A L L A : S T A R T I N G C O N D I T I O N S Journal A. I. . E.

value the current during the intermediate stages rises to a higher value than when the field is open-circuited. On the other hand, it will be noticed that with the field closed through a resistance high enough to allow of the machine being pulled into synchronism, a higher value of speed is reached with a given current than with the field on open circuit.

As the machine experimented on was provided with interpoles, it was thought desirable to try the effect of short-circuiting the interpole winding. In Fig. 11 are given four curves, two of which are for the sake of com-parison reproduced from Fig. 10. It will be seen that the worst results are obtained with both main and inter-pole fields short-circuited, and that the short-circuiting of the interpole windings alone does not produce any very marked effect, and is not sufficient to prevent the machine from running up to syn-chronism.

SUMMARY OF CONCLUSIONS REACHED

1. During the initial stages of the starting period the field should be kept open. If the induced voltage exceeds the limit of safety, a field break-up switch should be provided.

Closing the field circuit not only largely increases the current during the initial stages of the starting period, but may entirely prevent the machine from running up to synchronous speed. This is due to the single-magnetic-axis effect of the field winding.

2. If the field is kept closed and the machine only reaches a speed in the neighborhood of half-synchron-ism, there is no tendency to lock into exact half-synchronism.

3. There is a distinct advantage in short-circuiting the field after the field has reached a value not differing greatly from synchronism. This will greatly facilitate the final locking into synchronism.

BROADER TRAINING OF ENGINEERS

BY W. I. SLICHTER Professor of Electrical Engineering, Columbia University

THE report of the Development Committee of the Institute as approved at the Lake Placid Con-vention, contained a section calling attention to

the fact that "engineers do not participate as actively or as prominently in public affairs as they should and that both the public welfare and their own individual advancement would be promoted if this condition could be rectified."

One of the reasons given for this condition was: "too great technical specialization in the engineering cur-ricula of our technical schools and colleges which tend to narrow the vision of the engineering students."

To counteract this tendency it was stated that the Committee would welcome the establishment, at the earliest practicable date of a normal six years' collegiate course in engineering, two years of which at least should be devoted to training in the humane arts and sciences, while the last four should be devoted to a sound train-ing in the sciences and in only the fundamentals of diversified engineering.

Since the Development Committee has called at-tention to this idea of broadening the training of the engineer, the membership of the Institute should be interested in investigating how such a scheme would work out in practise. To this end there is presented herewith a schematic diagram in a new form, so that he who runs may read, showing the new six year course for engineers which was inaugurated at Columbia Uni-versity about four years ago. This method of presen-tation is interesting in itself and was designed to enable the busy Alumnus to grasp at a glance what the in-stitution is doing to the younger engineers.

The diagrams show how the student's time is divided, three years in college and three years in professional work, and the subjects taken each year,

weighted in proportion to the time assigned to them. At the end of the first professional year, the fourth

year of residence, the student receives an A. B. degree and here a process of natural selection occurs, the man not suited to engineering work usually decides to take

PRE ENGINEERING COLLEGE COURSE

1st Year

3rd Year

Eng. Hist. Mod. Lang. Phil. Math. Ph. Ed.

Eng. Math. Chem. Phys. D'ft.

Math. Chem. Phys.

Mec

h.

Econ.

PROFESSIONAL COURSE

1st Year

Summer

Summer

Phys. Mech. Ε. E. Chem. E. LU

Mech. E.

DEGREE OF A.B. GRANTED

Ε. E.

Phys. Ε. E. C. E. Mech. E.

Ε. E.

.1st Year Phys. Ε. E. Mech. E.

DEGREE OF E.E. GRANTED

KEY

Block represents total time for subject including class-room,

laboratory, & preparation

Scale: Unit-one hour per week for fifteen weeks

10 0 10 20 30 40 50 60 70 80

C. E., Civil Engineering. Chem., Chemistry. Chem. E., Chemical Engineer-ing. Oft., Drafting. Econ., Economics. Ε. E., Electrical Engineering. Eng., English. Ilisi., History. Math., Mathematics . Mech., Mechanics. Mech. E., Mechanical Engineering. Mod. Lang., Modern Language. Phil., Philosophy. Phys., Physics. Ph. Ed., Physical Education.

his sheepskin and go into general business, having had a well-rounded scientific education already. From here on the training becomes more special and at the end of the sixth year the candidate receives the appropriate professional degree, in this case, "Electrical Engineer."