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tion of the load, the coal and water facilities of the location, the kind of fuel available, its calorific value and cost, the rate of increase of the load and a loadcurve showing the day of maximum output for the preceding year. These data are secured directly from central station managers operating systems in the middle-west by sending out blanks accompanied by a letter explaining the purpose and asking for their cooperation.

With this as a basis the student prepares a preliminary layout of his plant and calculations for his design. This is then gone over with the instructor, and a decision is made on the apparatus for his plant; also the type of system whether single or multiphase, the frequency and voltage, etc. The student then prepares, a list of the apparatus needed for its equipment which is brought to the instructor. He is then supplied with templates of standard apparatus and machinery which fit his needs from the files of the department.

The student arranges these templates on his drafting board and when he has secured a practical and proper arrangement, pastes them in place on his detail paper and draws in the piping, breeching, stacks, etc., and building.

The number of drawings required of each plant are five:

A plan, 1"-1 ft.
A sectional elevation, 1"-1 ft.
A wiring diagram, no scale.

A front and sectional elevation of switchboard, 13"-1 ft.

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A piping plan, "-1 ft.

In addition to handing in the required drawing at the completion of the term, he tabulates the calculation of apparatus and writes a discussion of the reasons why the various types of machines were chosen.

The templates have been made from blue prints secured from manufacturers of standard apparatus and machinery. These blue prints are then reduced to the " to 1 ft. scale either by the students or draftsmen and traced on tracing cloth. By this method there has now been collected a fairly complete series of templates of the standard machines. They include: Prime movers, sizes up to 1500 kw.:

Steam engines;
Steam turbines; Curtis, Parsons.
Gas engines; Allis-Chalmers, Westinghouse.

Water turbines.
Jet and surface; Wheeler, Worthington, Alber-

ger, Baragwanath. Pumps : Air, circulating, boiler feed; Dean, Blake, Worth

ington. Boilers, all sizes up to 550 h.p.:

Water tube; B. & W., Heine, Parker. Exciter-sets, sizes up to 100 kw.:

Steam-driven, motor-driven. Mechanical stokers and chain grates:

B. & W., Jones underfeed, Mackenzie, Roney. Steam traps:

For all sizes of pipes.

Feed water heaters; open and closed types:
All sizes, for plants up to 6000 kw.; Hoppes,

Conveyers :
Switchboard apparatus:
Weston, General Electric, Westinghouse, Whit-

ney, Bristol. Ground detectors. A. C. & D. C. voltmeters, ammeters, wattmeters, both indicating and integrating.

Power factor indicators.

Frequency indicators.
Knife-switches up to 2000 amperes, both single-
and double-throw and pole:
Oil-switches for voltages up to 60,000, of all

Overload time limit relays.

Lightning arresters.

Air-blast and oil-cooled, up to 1100 kw.,
Current transformers,
Potential transformers,
Induction regulators,

Arc light transformers and regulators. The templates for the switchboard construction are made to the scale of 14"-1 ft., which is the standard adopted by most drafting rooms. The wiring diagram is not a scale drawing. An effort is made, however, to have all apparatus in the same relative position as in the plant.

In addition, the department has on file a number of standard drawings of switchboard construction showing frames, bases, bus-brackets, fuse panels, etc. Also wiring diagrams for railway plants, singlephase, direct current, and also for power and lighting plants, substation wiring and construction. A complete file of catalogues and bulletins is kept to which the student has access.

With these sources at his disposal and the templates in blue print form ready to be used, the student quickly learns how to combine machines and apparatus into a practical layout or design.

The merit of the system is that it relieves the student of the drudgery of reducing all apparatus to scale, which would be an impossibility in the time allowed, and still retains all the valuable points to be gained from such design and the concrete expression of his ideas.

By increasing the number of templates each year and showing the students the work of the previous class, the designs increase in completeness and merit. The student is interested when he sees he is producing something making him of immediate value to an employer and strives to out-do previous work.

It also familiarizes the student with a standard drafting-room method and one he will undoubtedly have to learn soon after leaving college, if he does not while there. It also enables him to produce results quickly, an additional virtue which central station managers and manufacturers will place to his credit.

The success of the work is mainly due to the fact that the student feels that in solving a problem based

on actual conditions he is producing more than a mere design, something of tangible value. In many cases the student spends more than the required time upon this work and makes, of his own accord, additional views, such as a transverse section through the plant, a view showing coal conveyors and bunkers in detail, etc.

The writer plans that the future may allow him to expand this method to the extent of having the student estimate the cost of the installation and, perhaps, to calculate the return on the investment, assuming fixed charges and a proper operating cost. To the extent that it has thus far been carried, there is no question as to its value.

JOINT DISCUSSION. PROFESSOR RADTKE: I would like to say a word in regard to Professor Schuster's claim that ten is the number of students that can be taught to advantage at one time in a laboratory. I think ten should be the maximum, but as a student becomes familiar with the instruments and machines, the number can be increased. As the number increases toward the end of the college course, an instructor may have as many students inside the laboratory as it will hold. It is only essential for the beginner to have such exact provision as Professor Schuster has designated by

his paper.

PROFESSOR BRACKETT: We have always had a great deal of doubt about those students who naturally depend upon others to do the work for them in the laboratory. Even if only two are working in a

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