We connected an elbow to the boiler check on the inside of the boiler and carried the feed water as near to the surface of the water level in the boiler as possible before discharging it. After trying this we found we were able to make about two round trips without the engines failing. This experiment proved that the trouble was due to feed-water conditions. I then decided to deliver the water into the steam space in a spray and thus improve conditions still more. A copper pipe was connected to the boiler check, extending about 18 inches inside, with 3-inch holes drilled on the upper side to keep the water in suspension as long as possible, allowing the feed water to absorb heat from the high-pressure steam before mingling with other water in boiler. After applying feed water in this manner the trouble entirely ceased and from that day to this we have not had a minute's delay charged against these engines because of tube or boiler trouble.

Later on we had another engine giving trouble from tubes leaking, and in order to further demonstrate what could be done I decided to change the feed water and apply it in the same manner as in the other cases; after the engine came in leaking badly we made the change and sent it out without permitting the boilermaker to go inside to make repairs, the engine going out in the same condition as when it came in. The result was the leak stopped and from that time until engine went into shop, some six months later, we never found it necessary to send a boilermaker into the firebox. This convinced me beyond any doubt whatever that the old way was entirely wrong and I immediately ordered all our locomotives to have the feed water applied in the manner described. This order was put into effect about July, 1907, and in the spring of 1908 we had all of our power so equipped.

I have followed the matter up closely since that time and find our engines steam more freely, burn less fuel and reduce

boiler repairs to a minimum; where we were using five and six boilermakers on roundhouse running repairs we now have but two, one man days and one man nights, and it is very seldom that either of these men is ever required to go into a firebox. We have also found that about 90 per cent. of the foreign matter is deposited immediately underneath the spray pipe, or in the front course of boiler. We have since placed a pan under spray pipe to catch all deposits before allowing them to fall and mingle with the tubes. This can be cleaned be removing the dome cap or connecting a pipe and blowoff cock, so arranged as to carry it away. I am also informed that one railway which was troubled with bad water and boiler foaming that after applying feed water in this manner the trouble from foamy boilers was almost entirely eliminated, and I presume this is due to the fact that all solids or foreign matter are immediately precipitated and not allowed to mingle with the other water in the boiler.

The question has been asked whether the holes in the spray pipe will clog up and put the injectors out of commission. In the first place, if copper pipe is used, this is not apt to occur, as scale will not adhere to copper as readily as to iron or steel pipe. Also the spray pipe is so arranged that it can readily be removed if this condition should occur. In our three and one-half years' experience we have never found it necessary to remove one pipe from this cause.

Our records show that we have made a saving of at least 10 per cent, in fuel, 75 per cent. in boiler repairs, an increased tonnage of 10 per cent., and at the close of our ore season engines tie up in better shape than ever before. I am, therefore, thoroughly convinced that the only proper place to deliver feed water into a locomotive boiler is in the steam space, and the finer it can be broken up and held in suspension, the better results will be obtained.-By C. W. Seddon, Superintendent Motive Power and Cars, D., M. & N. Ry., Proctor, Minn.

Book Reviews.

Operation of Trains and Station Work. Compiled and edited by Frederick J. Prior. This book gives in detail the duties and qualifications of station employes, and general rules covering the manage

ment of railway stations; also instructions to freight and passenger conductors. It contains the Standard Code of Train Rules; trainmen's examination, compris ing a complete series of questions and answers covering the Standard Code of Rules; rulings of the American Railway Association; Interlocking Rules; Block Signal Rules; general rules covering the operation of trains and handling of freight and passengers; trainmen handling brakes; rules for giving first aid to the injured, and a very complete chapter on telegraphy. The book is well written and is a valuable treatise on the subjects to which it pertains. It contains nearly 300 pages, size 4 x 6 inches, and is nicely bound in flexible cover with red edges and gilt title. Published by Frederick J. Drake & Co., Chicago, Ill.

Construction and Maintenance of Railway Roadbed and Track.-This work has been arranged and compiled by Frederick J. Prior, associate member Traveling Engineers' Association, and author of Operation of Trains and Station Work, and gives an exhaustive description of railway surveys and construction. It treats of construction accounts, land, track, structures, supplies and equipment for field parties; table of ordinates to vertical curves, the six chord spiral, maintenance of way, testing steel, rail joints, laying tracks, easy rules, bridges and buildings, railroad curve tables, excavation and embankment tables, abbreviations used by engineers, track definitions, trestles, concrete, etc. The book is profusely illustrated, is well written, and should be a valuable aid to anyone connected with railroad construction and maintenance. It contains nearly 600 pages, sixe 4 x 61 inches, nicely bound in flexible cover with red edges and gilt title. Published by Frederick J. Drake & Co., Chicago, Ill. Twentieth Century Hand-Book for Steam Engineers and Electricians.-By Calvin F. Swingle, M. E. This is an enlarged and revised edition of this work. It treats extensively on the care and management of steam engines, boilers and electric machinery, with full instructions in regard to the intelligent management of all classes of steam engines, steam turbines, gas engines, air compressors and elevators, both electric and hydraulic, and contains a section on electricity that is of especial importance to all engineers. The different sections are followed by a series of practical questions and answers in order to facilitate the study of the sub

jects treated therein. From a copious index at the back of the book one may easily refer to the subject sought. The book is profusely illustrated, contains over 1,500 pages, size 4 x 6 inches, and is nicely bound in flexible cover with gilt edges and title. Published by Frederick J. Drake & Co., Chicago, Ill.

Metal Spinning.-Pamphlet No. 57, on "Metal Spinning," is one of Machinery's reference series, and because of the scarcity of literature on this subject it should be of unusual interest to metal workers and manufacturers generally. It contains a chapter on Principles of Metal Spinning, by C. Tuells, and another on Tools and Methods Used in Metal Spinning, by William A. Painter, and is made up of articles recently published in Machinery. The art of metal spinning was practically perfected long before press working of metals became commercially important, but metal spinning, being essentially a process requiring much manual dexterity and skill, declined relatively as a manufacturing method as press working developed. For making fine brass, copper and aluminum, ornamental hollow-ware metal spinning has never been superseded, and is now being revived in modern lines for other than ornamental work because of the advantages set forth in the opening paragraphs. The treatise is timely, interesting and instructive. Price 25 cents. Published by The Industrial Press, 49-55 Lafayette street, New York City.

Electricity's Secret Said to Have Been Discovered.

According to a press dispatch to the Indianapolis News, dated Chicago, May 25, Associate Professor of Physics at the University of Chicago, Robert A. Millikan startled his scientific colleagues and students when he announced in a lecture the night before that a single ion, the atom of electricity, had been isolated and studied, the ultimate electrical charge accurately measured and the actual structure of the charge observed for the first time. The statement as given is as follows:

Professor Millikan has swept away much of the mystery surrounding the nature of the electrical charge since the discovery of electricity. Besides capturing an individual ion, the long misunderstood carrier of electricity, he has viewed in his laboratory peppery specks of electricity on

charged bodies, disproving the theory that electricity is an "imponderable fluid." and upholding the indefinite "ionic hypothesis" of Faraday, who gave his theory to the world in 1830.

Proves Kinetic Theory.

Also he has proved the "kinetic theory," that molecules of air are in rapid motion, and has measured the "energy of agitation" of the molecules.

Professor Millikan's announcement is the result of an investigation on which he has been engaged intermittently for the last four years, and uninterruptedly for the last five months, during which he has had the assistance of Harvey Fletcher, of the physics department.

That the university professor has isolated and toyed with one of the elementary units out of which all matter is made is a conclusion to be drawn from the experiments, in pursuance of the recent trend of science, according to the University of Chicago authorities.

The actual catching of the single ions was accomplished by the introduction of a "droplet" of oil between the plates of a horizontal air condenser. The presence of the ions became apparent owing to the action of the oil particles.

Statement of Results.

In an explanation of the fundamentals of electricity, called for by some of the professor's auditors who were not members of the Sigma Chi society. Professor Millikan found it necessary to state that an ion was an atom, or piece of an atom, a molecule, or a group of molecules, which carried the electrical charge. Then he gave the following statement of some of his results.

"We have succeeded in isolating an individual ion and holding it under observation for an indefinite length of time-an hour or more if desired.

"We have been able to give every tangible demonstration of the correctness of the view advanced many years ago that an electrical charge is not a homogeneous something a strain in the ether' or an 'imponderable fluid' spread uniformly over the surface of the charged body, but that it has a definite, granular structure; consists, in fact, of a definite number of specks or atoms of electricity, exactly alike, peppered over the surface of the charged body. It follows, of course, that an electric current which is simply a charge in motion consists of a movement of these atoms of electricity through or over the conducting body.

Evidence Most Convincing.

"We have been able to bring forward new, direct and most convincing evidence of the correctness of the 'kinetic theory' of matter, for we not only have shown directly that a molecule of air is in rapid motion, but we have measured the order

of magnitude of its energy of agitation and find it to agree with the computations based upon the 'kinetic theory.'

Explaining the discovery of the granular structure of electricity, Professor Millikan said:

"This is not asserting anything about the ultimate nature of electricity, but is merely pushing the unknown down into these ultimate electrical units or atoms. As a matter of fact, we are pretty certain that all material atoms contain as constituents these ultimate electric atoms, and it is the vogue now to surmise that these electrical atoms are the ultimate units out of which all matter is built up.'

According to the Standard Electrical Dictionary by T. O'Conor Sloane, A. M., E. M., Ph. D., the term ions is defined as "the products of decomposition produced in any given electrolysis."

Overheating of Air Pumps.*

With the approach of hot weather the overheating of air pumps becomes a troublesome question alike to the enginemen and repairmen. With the initial high temperature of the air on a hot, dry day, added to the heat gained during the process of compression, it requires considerable attention to the air brake system in general to prevent the air pump from being seriously overheated.

As an air pump once thoroughly overheated is practically ruined until overhauled, it behooves all concerned to use all due precaution to prevent overheating.

Among the most common causes of overheating are: Insufficient lift of air valves, air valves stuck or broken, loose intermediate valve seats cutting off lift or intermediate valves, leak at discharge pipe connection to air pump, or at main drum, air end rod packing blown out and racing of air pump.

These defects are easily located and, if promptly remedied, will prevent overheating and prolong the life and efficiency of the pump.

One defect frequently found is air end rod packing blowing. This reduces the efficiency of the pump to a considerable extent and is sure to result in overheating. This defect is often overlooked, especially if the steam end happens to be blowing at the same time.

Another thing that should not be overlooked in the care of an air pump is its

*By Thos. J. Lyons, in The Frisco-Man.

passages, thereby destroying the efficiency of the pump. Oil sparingly at all times; "enough is as good as a feast." Keep a good oil swab on the piston rods. If the choke plugs in the oil cup become stopped

the pump, for after a certain speed is attained the pump is working at its full capacity, and crowding beyond the limit will result only in overheating and final failure.

hundred feet. All of the superstructure is of steel. The total cost of this bridge approximately (including the expense of getting the material on the ground) was about $300,000.

Large Order for Freight Equipment. One of the largest orders for freight equipment in the history of the Western railroads has been very recently given by the management of the Harriman Lines, and consists of 12,440 freight cars that

*By J. Mayne Baltimore, special correspondent to the Locomotive Firemen and Enginemen's Magazine.

completed, is one of the finest along the line of that road. It is very much like all the other stations on this route-being on the old California mission type of architecture. It is more than 250 feet wide, stretching along the track. This depot is of one story, all of the division offices being housed elsewhere. It is of solid concrete and stucco, covered with a Spanish tile roof. The baggage and express departments are housed in an extension. This new depot is an ornament to Sacramento.. The total cost was about $50,000.