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with varying load conditions.

Figure 2 illustrates a slightly different design of reaction type turbine installed in a power plant.

modern hydro-electric apparatus the efficiency Speed regulation is accomplished in this way of the plant becomes one of the first considerations, as every possible kilowatt hour of energy must be taken from the water. At the present time the combined overall efficiency of turbines and generators usually exceeds 85 per cent and the efficiency of the turbines is often 91 per cent to 93 per cent.

There are two distinct types of modern hydraulic plants; the impulse type and the reaction type. The impulse type is suited to high heads such as are found in the mountain streams on the west coast. In this type of turbine the water comes into the machine through a nozzle at an exceedingly high velocity. The stream is directed against a series of buckets or blades mounted on the periphery of a wheel and in this way produces motion. For maximum efficiency the peripheral speed of the runner should be approximately one-half the velocity of the water.

The water which is in the forebay just passes through a rack which prevents logs

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In the reaction type turbine a much larger volume of water with a lower head flows horizontally or vertically through a runner consisting of curved blades. A machine of this type is shown in figure 1.

Surrounding the runner are a number of pivoted gates so arranged that the flow of water through the machine can be regulated. These gates are operated by means of the arm which extends out over the top of the machine and is attached to the governor.

Fig. 2.

and debris from going into the turbine. In some designs the water is then led through a concrete or sheet steel conduit called the penstock to the turbine.

The machine illustrated in figure 2 is immersed and the runners are not encased as in figure 1. Figure 1 is a vertical type single runner turbine while that in figure 2 is a double runner horizontal machine.

From the penstock the water in the case of figure enters a spiral shaped shell containing the runner, which is called the scroll case. The water then passes into the runner and down into a steel or concrete tapered duct known as the draft tube.

The design of the draft tube is of great importance. Its function is to reduce the velocity of the water so that nearly all of the energy may be taken out of it. From the draft tube the water is discharged into the tail race and proceeds down stream. It is this type of turbine which is used exclusively for the low-head plants which have been built. in the middle west.

H. W. MEYER.

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The Christmas holiday season is to most people a time for making resolutions to do something or to give something that will bring pleasure to friend or loved ones. To bring pleasure to others is a worthy resolution and, like a boomerang, it circles around and returning brings pleasure to the sender.

Christmas is a time when differences are forgotten and to do good is uppermost in the minds of all. This is the Christ spirit and the Golden Rule, "Whatsoever ye would that men should do to you do ye even so to them," is thus exemplified.

LIBRARY NOTES.

The present slogan for our study room must be "The greatest good to the greatest number." To that end the librarian has attempted, during the last three months of transition, to adapt the facilities of the library to the needs of the widely different groups which come to study there. In most cases her attempts have met with hearty co-operation. If for the two hundred students of the Automobile Department there could be provided two hundred copies of Dyke's Automobile Encyclopedia everyone would go away satisfied and happy. That is an impossible feat and so we are called upon often to substitute

some other book, a magazine, or material from the clipping file, for the book called for.

Dunwoody Library is equipped with all the necessary tools that a school library should have, except a catalogue. A start has been made, and the books classed in the "500" classification (mathematics, mechanical drawing, physics and chemistry) have been catalogued. The work will continue until the entire collection is catalogued.

Bound periodicals form the best reference material obtainable, particularly for a special library, as ours is. With the needs of the future in view, it has been decided to bind one periodical for each trade now taught at Dunwoody Institute. The magazine chosen has been selected on the basis of being best adapted to the needs of the students. All of these magazines except, "Baker's Weekly," are indexed in "Industrial Arts Index," which is the "open sesame" to all trade periodicals. The librarian cannot urge too strongly that the students as well as the instructors become acquainted with this index if they do not already know how valuable it is.

Following is a list of the periodicals to be bound: Inland Printer Building Age Electrical World American Machinist

Automotive Industries
Bakers Weekly
Metal Worker

Applications are being received almost daily for entrance to the baking class. There is every indication that we shall have every place taken by January 2nd. In addition to the twenty men that will remain, we shall accept about fifty new students. Additional equipment is being installed in the department and additional men are being added to the teaching force to aid in handling the large class in January.

WANTED—A boy who, when he does not know a thing, says, "I don't know," and when he makes a mistake, says, “I'm sorry," and when he is asked to do a thing, says, "I'll try."

PLUMBING OF YESTERDAY AND

TODAY.

A few short years ago a man in Chicago closed up his little tin and sheet-metal shop and journeyed "back east" for just one purpose, and that was to learn how to properly line a wooden bath-tub shell with sheet copper so as to make a neat and workmanlike job.

He learned how; came back to Chicago and for a time made the lining of tubs a side line with him. In time the business grew until it was necessary for him to spend all of his time lining bath tubs. From that start, one of the largest manufacturing concerns in plumbing goods grew.

From the copper-lined tub we graduated to the iron-enameled tub, with a separate wooden rim; finally the rim became part of the tub and of the same material. Then came improved designs in enameled iron bath tubs, the early tubs being placed on feet, then came a base on which to place the tub, and now we are using white enameled bath tubs that are placed in a recess, or a corner or against one wall of the bathroom, with tile floors and walls built right up to the tub, so that there is absolutely no place in or about the tub offering refuge to insects or bugs of any kind. With this style tub, the working parts are placed in a small compartment with a door opening into the adjoining

room.

Bath tubs are also made of china in the same form as that described above and at the present time there is no more sanitary fixture than either of the above described tubs.

Similar improvements have been made in the other plumbing fixtures and at the same time a great deal of progress has been made in the manner of installation and the kind of materials used.

Truth to tell, the plumber of today is wrongly named, for we are told that a plumber is a worker in lead and there are hundreds of the plumbers of today who work from one year's end to the next without even touching a piece of lead; there are many others who do a very little lead work; and very, very

few whose lead work requires more than five per cent of their working time.

Thirty years ago the water pipes and the waste pipes within the building were of lead. Soon after that date the water pipes became galvanized iron. Up until ten years ago, 95 per cent of the homes had lead waste pipes for the laundry tubs, kitchen sinks and bathroom fixtures and that percentage has been gradually changing until now we find that less than 5 per cent have lead waste connections. Galvanized iron pipe is being used almost entirely and with highly satisfactory results.

And while the materials for the craft have been improving, so, too, have the tools. A few years ago the thread-cutting tools in every-day use were the so-called solid die pattern and cutting pipe threads with tools of that age was real work. The die was then improved and became an easier cutting tool, but this in turn has been almost replaced by the narrow receding dies which automatically work outward as the thread advances. A companion worker to the threading machine is the pipe cutter, first made with wide, heavy cutting wheels, and now made with narrow, razor-edged blades that do the job with onehalf the effort of the old.

And now we have a machine to do that work. Of course, there have been power pipe-threading machines in use for many years, but they have been big, heavy outfits. Now we have a motor mounted on two small wheels looking for all the world like a small cannon, which attaches to the die stocks usually operated by hand, and cuts the thread with no greater effort than the pressing of the button. With all of these improvements today, what will tomorrow have for us?

W. W. Hughes.

MODEST DESIRES.

Fond Mother-"Dorothy, if you are bad you won't go to heaven. Don't you know that?"

Little Dorthy-"Well, I've been to the circus and the Chautauqua already. I can't expect to go everywhere."-Orange Peel.

Great Benefactors

Under this heading, from time to time, we will publish something about some of the great men who have benefitted the world and humanity.

JAMES WATT. (Biography)

James Watt, the Scottish inventor and engineer, was born in Greenock, January 19, 1736. Of the many things which he discovered and improved are the steam engine, the indicator to show the pressure in the boiler, the method of analyzing water and a uniform system of weights and measures for scientific

purposes.

For

As a boy, Watt was very delicate. this reason he was mostly for himself. To pass the time he read and studied everything that came into his hands. In this manner he became able to solve anything that was brought up.

Watt's father, being a successful shipbuilder, gave Watt an opportunity to go into the shipyards and learn the use of tools. This he did very readily, making use of all the machinery and apparatus placed before him. Even the workmen noticed his skill and often said: "Jamie had a fortune at his finger ends."

He went to Mr. M'Adam's Commercial School. As he was in poor health he often had to miss his classes. This affected his standing, making him appear stupid. After one year he returned home.

In Greenock he attended the grammar school. On entering here he seemed to have left his dullness at M'Adam's for he turned out to be very bright in mathematics. In addition to mathematics he took up Latin and Greek.

When he was strong enough he wandered among the locks and valleys of the neighborhood. In this manner he attained knowledge of the flowers and trees. Often at night he rambled, during which he was chiefly attached to the impressive mechanism of the skies. At times he would drop in at some fisherman's cottage to hear the stories which they told.

At eighteen financial reverses of his father made him depend upon his own resources. At once he chose to become a mathematical instrument maker.

He went to Glasgow to seek work. Business being dull, he hired out as an optician. Here he befriended Dr. Dick, of the university. After a year in Glasgow he went to London to seek better opportunities to learn his trade. Here it was also difficult to obtain work for he was expected to serve seven years as an apprentice. At last he received work from Mr. Morgan. After a year's time he was to pay twenty guineas for the instruction. Here he made very many accurate instruments, and in a half year he was as good as a seven-year apprentice.

In 1756 he returned to Glasgow to open up a shop. There being so much jealousy in his trade and as he had not learned there, he was unable to do so.

Through the influence of Dr. Dick, Watt received work at the university. He skillfully did this work and as his reward he was given the title Mathematical Instrument Maker. At the university he became quite prominent with the professors and students for his knowledge of various subjects.

One day Professor Robison, of the university, suggested some improvements on the steam engine. Watt declared he knew little about the matter. As a result of this discussion he started to look up information about the steam engine. Later a small model came into his hands for repair. Through it he gained broad experience.

Watt became a partner with Mr. Roebuck, who was to finance the improvements. Success did not come as Watt thought, so Mr. Roebuck was forced to give up his plan. The times were hard then. Watt was forced to go surveying. He accepted employment with the Glasgow magistracy. In his engineering career he constructed the Monkland Canal,

on which coal is brought to Glasgow. After three years of surveying Watt again put his thoughts on the improvement of the steam. engine, with the help of Mr. Boulton. Mr. Boulton owned a large iron works which contained many skilled workers. With the help of a true cylinder Watt constructed the steam engine that became a profitable machine.

In 1800 Watt turned over his business to his son. In Doldwlod, on the banks of the Wye, he bought a home. Here he spent the remainder of his days.

He died August 19, 1819, at the age of eighty-two, and was buried at Handsworth Church. In Westminster Abby there is also a monument to his memory.

WILLIAM E. ZIPSE.

What Is the Value of "Allied" Study to the Shop Mechanic?

By WALTER S. MILNOR.

Undoubtedly the question, "Do I have to take Shop English, Arithmetic and such subjects?" has been asked more than any other by entering student, particularly by men. who have come for short course periods and desire to spend a maximum time in actual work. The answer, of course, is always "Yes!" But when that "Yes" is uttered, I have often thought I should like to explain in detail just why the subjects the student would avoid are the very ones he will in later years regret if he fails to take. However, before I try to "build-in" a foundation as to the "why" of these shop-allied subjects, let me try to show what the automobile apprentice mechanic will have to tread through.

I believe it is safe to say that Americans have the "Automobile Bug." Everybody is a prospect in the automobile business; even the most lowly of workers, plodding his way to business in the morning, cooly figures when he will ride to work in an automobile. The fact is, he may already have laid by a goodly sum toward his first car. If the truth be known, one will have a hard time finding the family that can not boast of an automobile or one in the possession of a very near relative. This desire for car ownership soon musters an army of owners numbering tens of thousands, all individuals mind you, who have but the scantiest idea of

proper maintenance. The cry for "good" automobile mechanics naturally arises from every quarter. It starts its murmur in the very household of the modern young American. "Father" wants to know if "Johnny" can do so-and-so about the car. Johnny thinks he can, and it becomes small wonder that when Johnny finds his studies a little dry and irksome at school his mind travels to the idea of a position in the "automobile business."

But Johnny isn't the only one who hears. the call of the automobile. There are many, years old than Johnny, who have had "dead end" jobs and look upon the automobile as an opportunity to seek employment with better chances of advancement. These fellows are almost always young men, under thirty, who left school between the seventh and tenth grades for one of the three common reasons, low family income, desire to be an earner or a failure in school studies. Most of these men have but scant knowledge of the automobile industry, but having heard of some one making a signal success and are ambitious to try it themselves. Some do not know whether or not they are "fitted" for "mechanics," at least this is the way they express it. You can't help but admire them, however, for having the courage to attempt the occupational change, for think how they must feel if "somebody" who claims to

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