THE "TRIUMPH" IRON-CLAD DYNAMO.

RECOGNIZING a large demand for distinctively low-priced dynamos and motors that will do good work, the Triumph Electric Company, of Cincinnati, Ohio, has lately produced a machine of excellent design and workmanship, and capable of being sold at a very low price. The practical working of the machine has been exclusively considered and every point of mere beauty that would increase the cost has been omitted. That the result is far from unpleasing in appearance, however, may be seen by reference to the illustration showing the finished dynamo. The company's factory is equipped with modern machinery especially adapted to making these particular dynamos and motors, with the necessary accuracy to secure the best results. The designers and builders have had more than ten years' practical experience in the successful designing and building of electric lighting and power machinery and the knowledge so gained has enabled them to embody in the design of the Triumph machines many points of excellence found in others while avoiding certain common defects, in addition to several features of merit distinctively their own.

All Triumph dynamos and motors are provided with dust-, dirt, and moisture-proof covered commutators, and carbon brushes brought in contact with the commutator end on, and requiring no filing or attention whatever and the brush holders are fixed and immovable. The spider is made to fit the shaft by casting it on. The shaft is first prepared by having three longi. tudinal grooves cut equidistant and somewhat shorter than the hub of the spider, into which the metal flows in casting, and shrinks, holding it firmly against lateral or end wise movement. The spider is of bronze. The armature-core is built up if thin discs of soft charcoal iron, toothed on their outer circumference to receive the wire. The conductors are thus embedded in the iron, and protected thereby, and are in such close proximity to the pole-pieces as to leave air space sufficient only for clearance in rotation.

The discs used in these ammeters are slotted by a machine one at a time, so perfectly that when placed on the spider no filing or cutting is necessary to complete them. Mica insulation is used inside and out. The winding is simple, the connecting wires

a rectangular form of cast iron, each layer being saturated with a special insulating compound. When the winding is completed, the coil and form is placed in a steam-heated oven, and kept there until the last particle of moisture is driven out. The coil is then removed from the form, and, after a first covering of heavy fullerboard, is carefully wound with three layers of covering tape, each layer covered with shellac, and again put in the oven and baked until thoroughly hard and dry.

Constructed in this way, and so placed on the poles that no part is in contact with the iron, a burn-out is claimed to be impossible.

PARAGON REFLECTORS.

The American Reflector and Lighting Co., of 80 Jackson street, Chicago, Ill., have issued a 32-page illustrated catalogue describing their "Paragon" reflectors for electric, gas and oil lighting. These reflectors are adapted to general uses, utilizing all the light and distributing it where it is wanted. They are made in a great variety of forms, depending upon the position in which they are to be used; also upon the area and shape of space to be lighted, the object being to have each reflector to give the best possible results, all things considered. They are well made on scientific principles and in a great variety of styles.

THE WHITE ADJUSTABLE LAMP HOLDER.

Messrs. O. C. White & Co., of Worcester, Mass., have issued a catalogue descriptive of their adjustable holders for incandescent lamps. The device consists of a combination of tubes and joints modeled after the principle of the human arm, with a ball and socket joint at the shoulder, a swivel joint at the elbow, and a wrist joint, which can bring the lamp into any position within its sweep. Each joint of the mechanism has an elastic pressure which is enough to hold a heavy lamp and shade firmly, and still will yield to a moderate force when it is desired to change its position. Both the upper and lower arm can be made longer or shorter at will, by simply sliding through the swivel joint. All the working parts are of metal, made interchangeable; insulating bushings protect the conducting cords, and ample provision is made for any possible wear by prolonged use.

THE NATIONAL ELECTRIC CO., Eau Claire, Wis., will move their Chicago offices to large and more convenient quarters on the thirteenth floor of the "Old Colony" building, on April 15th next. Messrs. Horne & Martin, their General Sales Agents, have just closed a contract with the Leland Hotel, Chicago, for the furnishing of two of the improved type National bi-polar incandescent dynamos.

MEMPHIS, MO.-A contract has been closed with the Franklin Electric Co., of Kansas City, Mo., for an incandescent electric lighting plant including new steam plant and Edison incandescent dynamo and construction.

CUTTER'S MAST-ARM PULLEY.

THE extensive and continued use throughout the country of lamp supporting pulleys has shown that a simple and reliable safety pulley fills a most decided need. But while this form serves the purpose nicely wherever the lamps are hung from suspension wires, there has been a growing demand for a similar device to be used in connection with the mast-arms which are coming into more general favor. The result is shown in the accompanying illustration, being a modified form of the Cutter lamp-supporting pulley and retaining the same simple and automatic action.

The new form has already been given rigid tests in various parts of the country, with most satisfactory results. It has a clamp which not only supports the pulley but also serves as a headpiece for the end of the arm, so that the bracing can be done from this point. All

parts are well made and japanned, the supporting hook-knob being of malleable iron. This new pulley seems to be a practical device and the maker, George Cutter, of Chicago, expects a large sale.

THE GRAHAM "ELECTRIC" TRUCK.

THE accompanying illustration shows a street railway truck especially adapted to electric roads, manufactured by the Graham Equipment Company, of 258 Washington street, Boston and 741 Drexel building, Philadelphia. Its design, as will be seen, is very simple. It has a strong brake gear with few parts, and will, it is claimed, carry the car body without oscillation of any kind, as the reciprocal arrangements of straight leaf springs cushioned on spirals neutralizes the "teetering" motion.

It has but sixteen bolts, and no rivets, hot or cold, to rust or rattle loose. Its pedestal jaws fit down over the axle box and prevent the car from surging forward on the springs when the brakes are applied. The truss rods extend continuously from one

THE IMPROVED "CHICAGO" TROLLEY CLAMP.

The accompanying illustration shows an improved form of the "Chicago" trolley clamp, now being introduced by the inventors, Messrs. J. S. Gustin & Co., Chicago. While the clamp itself has been in use, especially on some of the Chicago trolley roads, for some time, giving excellent satisfaction, the inventors have lately made several desirable changes in the design, one of which consists in so modifying the shape and dimensions of the tongues, as to expose the under surface of the trolley wire to contact with the wheel throughout the entire length of the clamp, thus avoiding the injurious arcing of the trolley wheel when passing hangers. Another improvement consists in doing away with the off-set in

CHICAGO" TROLLEY CLAMP.

the clamping nut. This not only adds to the symmetrical appearance of the clamp, but also avoids the striking of the nut by the wheel flanges, in case the wheel should not run true. Finally, the tongues on the inner surfaces of the clamp have been given a slightly greater angle, which increases the gripping power of the clamp to a considerable extent.

ELECTRIC APPLIANCE CO.

The Electric Appliance Co., Chicago, are beginning the usual spring campaign with the "Swinging Ball" lightning arrester and are meeting with their usual success. In fact the Swinging Ball Lightning Arrester has held the field for so many years that it does not now require any very aggressive work to call forth a large demand for this desirable specialty. As is well known the Swinging Ball Lightning Arrester is particularly well adapted for a line arrester and is almost exclusively used in this way. The manufacturers promise something new this season in a station arrester built upon an equally effective principle.

AN EASTER OFFERING.

GLASS pens have heretofore been considered something of a luxury even by the most affluent of our citizens; but by the action of the Law Battery Co., 85 John street, New York, these are now placed within the reach of all who can afford a few pennies for postage, provided they quickly make known their wishes. The pen which this company so freely offers will prove a boon to many who have suffered in times past because of the weariness of writing, while the young idea of the household may take its first lessons in the art, even if only by tracing the letters which form a striking advertisement in the interior of the holder.

NEW YORK NOTES.

MR. G. H. ALMON, formerly of 136 Liberty street, selling agent for the Belknap Motor Co., has sold to the Bishop Gutta Percha Company of this city two 11 k. w. dynamos and a 10 h. p. motor.

MR. LOUIS O. BREWSTER, 136 Liberty street, has become New York manager of the selling agency of the Belknap Motor Co. and the L. P. & D. Transmitter Co. He is associated with Mr. G. H. Almon, who has assumed charge of the Boston office.

THE METROPOLITAN TRACTION Co. will, it is said, soon adopt a conduit system for one of its roads in New York City, and the Twenty-Third Street is mentioned. It is also stated that the Siemens-Halske system as used at Buda-Pest may be given a trial.

THE AMERICAN MFG. & ENG. Co., jobbers and manufacturers, consulting and electrical experts, have opened offices at 143 Liberty street (the Central Building), where they will be glad to hear from the profession and trade. Mr. W. M. Miner is the electrician and general manager.

THE BISHOP GUTTA PERCHA Co., 420-6 East Twenty-fifth street, has issued a very neat and handy little pamphlet of "Tables, Rules and Information" for architects and electrical engineers. It includes the rules of the New York Board of Fire Underwriters, and rules for wiring on the basis of 55 watt 16 c. p. lamps, etc.

THE GENERAL ELECTRIC COMPANY have perfected their woven wire dynamo brushes for all of the machines they manufacture with the exception, of course, of the arc dynamo. The brushes are made of fine wire gauze, which is first wound into rolls, and then shaped into brush form under heavy pressure. It is said that they are smooth, give excellent contact, run cool and do not fray.

THE DIRECT U. S. CABLE Co. (LTD.) circulates a neat little slip in which it quotes the following from one of the New York dailies:-"The Direct Cable Company achieved another victory over its competitors yesterday in transmitting to the United Press its announcement of the result of the Oxford-Cambridge boat race on the Thames. Ten seconds after the dispatch was filed in London it was signaled to the United Press office in this city, thus anticipating the announcement by other lines from three to ten minutes."

WESTERN notes.

THE iron roof over the dye house for Geo. C. Hetzel & Co., at Chester, Pa., will be furnished by The East Berlin Iron Bridge Co., of East Berlin, Conn.

THE METROPOLITAN ELECTRIC COMPANY are getting in a stock of porcelain floor tubing of all sizes, to meet the requirements of the Board of Underwriters.

THE MANHATTAN ELECTRICAL SUPPLY CO. have found it necessary to remove to more commodious quarters, and are now on the ground floor of 32 Cortlandt street, New York City.

MR. JNO. L. MARTIN, of Horne & Martin, Chicago, who suffered the loss of his left arm on March 22nd, is reported as doing nicely, and it is hoped that he will soon be able to attend to business.

THE HOME TELEPHONE COMPANY, Bloomington, Ill., has been incorporated, the capital stock being $30,000. The incorporators are Jas. B. Taylor, Owen Scott, A. B. Hoblet, F. M. Funk, H. C. Demotte and B. M. Kuhn.

THE METROPOLITAN ELECTRIC COMPANY note that the dynamo and motor makers are using P. & B. armature varnish with satisfactory results; the larger companies buying in barrel lots. The company carry a full stock of the P. & B. specialties.

THE BUCKEYE ELECTRIC Co., 401-404 Cuyahoga Building, Cleveland, O., has just issued two neat little circulars, one referring to its electric railway incandescent lamps which are anchored at the side; and the other to its special coiled filament lamp for decorative, steamship and kindred lighting where a short lamp is needed. This special lamp is but 44 inches long, while the standard average type is 51⁄2 inches.

THE STROWGER AUTOMATIC TELEPHONE EXCHANGE of Chicago has ordered one hundred No. 1 Standard magneto telephones from the Western Telephone Construction Co., of Chicago, to replace the battery telephones of the Exchange at La Porte, Ind.

LINCOLN & CO., Chicago, have opened offices at 934-935 Monadnock Block, and will act as manufacturers' agents for high-class electrical goods. They have secured the agency for several important specialties and Mr. Lincoln's extensive acquaintance among the trade, coupled with low prices for first-class goods, should secure them a liberal share of the business.

THE CENTRAL ELECTRIC COMPANY are in receipt of the following communication from one of the leading electric light companies in the country: "We are obliged to you for your calendar for 1894. We were on the point of writing for one, because it was the most sensible and complete one we had last year, and we hoped you were printing one of the same style for this year." The Central calendar is certainly a complete electrical calendar, and any one in the trade who has not received one, should request the Central Electric Company to forward one at once.

FISHER & PORTER, 1025 Monadnock Block, Chicago, report that they see evidence of a good business in the immediate future. They are equipping with machinery, for W. H. Roessle, of Pittsburgh, a gold mine at Tellico Plains, Tenn., and have supplied Kotine, a new material for painting iron structures, for the new Lincoln Park bridge, recently erected by the Pittsburgh Bridge Co. They have the contract to supply two 75 h. p. M. A. Green engines for the Leland Hotel in Chicago, and have several contracts of a similar nature ready to be closed.

THE ELECTRIC APPLIANCE COMPANY are just placing upon the market something which is entirely and absolutely new. This means that it is not an improved form of something else that has been on the market but is in itself an entirely new production; something that has never been used and probably never thought of before. It is the Allen soldering stick; a soldering flux in solid stick form to take the place of resin, acids and soldering salts. It is put up in candles one inch in diameter and six inches long and is applied by simply rubbing on the joint when heated. It is a wonderful time-saver and is said to be actually cheaper in first cost than soldering salts or acids, and not in any way to corrode the joint or affect the insulation. The Appliance Company are furnishing small sample sticks free on application.

MONTREAL NOTES.

MR. J. E. WILSON, of the Pettingell-Andrews Co., of Boston, who was a recent visitor to Montreal, reported business good and the outlook bright.

MR. H. F. KELLOGG, general selling agent of the Whitney Electrical Instrument Co., was in the city last week. Mr. Kellogg finds a growing sale in Canada for the Whitney instruments which are giving universal satisfaction.

MR. JOHN FORMAN, of Montreal, has entered into business as importer and dealer in electrical supplies and has taken a commodious store at 650 Craig street in that city. Mr. Forman is well known to the Canadian trade and starts business under favorable auspices, having secured the Canadian agencies for Messrs. Crompton & Co., the Edison and Swan United Co. and several other well known English concerns. United States manufacturers who desire to introduce their goods in Canada are invited to correspond with him.

THE BELL Telephone Co., of Canada, have commenced suit against the Montreal Street Railway Co. to recover over $27,000 damages, the cost of putting common return wires on their telephone system in Montreal, up to the date of entering the action. The Bell Telephone Co. state that the introduction of the trolley system of electric traction by the Montreal Street Railway Co., has necessitated the installation of the return wires and the abandonment by them of the use of the ground as a return. They claim that, having rightfully enjoyed the use of the ground for this purpose from the time of the establishment of their telephone system in Montreal, the Street Railway Co. should therefore reimburse them for the expense of making the change. Heretofore, the suits brought by telephone companies against electric railway companies have been for injunctions to prevent the introduction of the single trolley system, and this is believed to be the first time-at least in Canada-that recourse has been had to an action for compensation for the cost of altering the telephone system to overcome the interference of the trolley system.

Departmental items of Electric Light, Electric Railways, Electric Power, Telegraph, Telephone, New Hotels, New Buildings, Apparatus Wanted, Financial, Miscellaneous, etc., will be found in the advertising pages.

Vol. XVII.

DISCHARGE OF FIELD MAGNETS WHEN CONNECTED TO BUS BARS.

BY

Min A. Authony.

FIND in Mr. Herrick's paper on "Central Station Switch Boards," which was read at the Washington meeting of the National Electric Light Association, the following passage referring to the method of handling dynamos where the fields are excited from the bus bars :

The disadvantage of this method is, that the field is on, although the dynamo may be shut down, and it is necessary to discharge it through a bank of lamps or other resistance by means of a field break switch. This method of discharge, although safe, might cause trouble should the bank of lamps be disconnected or otherwise out of order.

This passage calls to mind discussions that I have many times had with electricians as to the necessity of discharging the field through a resistance. Why not short circuit it? The impression seems to be quite general that a resistance approximately equal to that of the field should be provided, and the switch which breaks the field circuit arranged to discharge the field through this resistance. I have never been able to obtain a clear statement of the reason for this belief. The Mather Electric Company has for several years constructed the field rheostats for large machines, and especially for 500 volt generators, to admit of the connections shown in the sketch. As the rheostat lever is turned toward the right, resistance is introduced

No. 310.

into the field circuit, gradually reducing the current until, when the lever passes off the point A, the circuit is broken. But at the instant of passing off the point a, contact is made with the point B, which short circuits the field and permits of its discharge through a circuit CDE F, of practically no resistance.

I have been informed that the electrical engineer in charge of the erection of one of the Mather plants insisted that their agent who was having the plant installed, should have a resistance inserted in the branch B E. The paragraph quoted at the beginning of this letter recalled this matter to my attention and leads me to state the theory of the action as I understand it.

When the field circuit is broken, the dying out of the magnetism develops an E. M. F. in the field windings tending to produce a current in the same direction as that which magnetized the field. If no path is offered through which this current can flow, this E. M. F. develops a difference of potential between the field terminals and between different parts of the field winding, that may amount to hundreds or thousands of volts, sufficient to break down the insulation and cause serious damage to the field coils. If, however, a path of no resistance, as C D E F, is provided. between the field terminals, the E. M. F. will be almost wholly employed in producing current through that circuit, and no appreciable potential difference will be developed The current through the short circuited field can never be greater than that which originally excited the field, because it is produced by the falling magnetism, is in the same direction as the exciting current, and, if it should equal it, the magnetism could not fall. Further, the potential difference between F and c can only be such as would maintain his current through the resistance C D E F, and the smaller this resistance, the less this potential difference. Further still, the less the resistance in C D E F, the greater the current developed by the falling magnetism; the greater the current the more slowly does the magnetism fall, and the more slowly the magnetism falls the less is the E. M. F. There is every reason then for making the resistance of C D E F as smail as possible.

This arrangement of the rheostat saves the necessity of an extra field switch, and insures the partial cutting down of the exciting current before it is finally broken.

caused by contact with the iron pipes in the building. They are concealed, and electrical methods must be used for their detection and location. The larger wires, carrying heavy currents, are generally run in places where they are not apt to be disturbed and their extra thickness of insulation is more or less a protection against mechanical injury. The result is, that most of the grounds occur in fixtures or in drop cord sockets resting against gas fixtures or steam pipes.

In practice it is usually better not to test large sections. of the installation at one time when the current is on, because of the burning of connections when circuits carrying, say, ten amperes or more are opened. The wires too are heavy and frequent bending is liable to break them.

Testing with a magneto, or with a galvanometer and battery generally necessitates a search for something on which to ground one side of the testing apparatus and running a wire to it, all of which takes time. On alternating current circuits this is of course the best method, as there is no electrical connection between the primary and secondary circuits. But in direct current plants the ground detector may be used as the necessary ground. When current is on, the only apparatus needed is a socket wired with a few feet of wire or cord and a 16 c. p. lamp. When current is off, a magneto must be used instead.

Referring to the accompanying diagram, let the cross denote a ground on the negative side of the system. When the ground detector switch is closed, current flows from the dynamo through the ground detector lamp to ground, entering the system through a ground at some unknown

GR.

LOCATING A GROUND.

point. Now if a lamp be placed anywhere in this circuit, say at the cutout, it will light up and indicate the faulty circuit.

If the circuit is broken at the cutout and the lamp cut in, the lighting up of the lamp to low incandescence will locate the ground on that particular branch. Taking one cutout at a time, both sides are opened and the lamp placed in the negative side of the cutout, assuming of course that the ground has been shown to exist on the negative side of the circuit. The lamp will show at once whether that branch is clear or not. If no lamps are burning on that circuit, the positive wire need not be opened. Each circuit is tested in a like manner until the trouble is located in some one of them when it can be further located by the usual methods. Of course the absence of results shows that it is somewhere on the mains and feeders.

Testing may be begun by testing the main cutouts. The arcs formed when the heavier currents are broken burn the binding posts. The wires are No. 12 and larger and frequent bending is apt to break them off; besides, the trouble will usually be found in the end on the smaller

branch circuits. In central station work the building

should of course be located first. Where plug cutouts of the Edison type are used, the testing lamp may be screwed directly into the cutout. In city plants there are always a few lamps burning and it is very desirable to interrupt

the service as little as possible. One man can cover as much ground with a lamp as two can with a magneto. If the ground is of very high resistance, a cheap galvanometer should be used instead of the lamp. The time at each test is small, but for an entire plant, it amounts to a surprising difference.

It may be urged that grounding the system in this way in order to test it, is bad practice on account of fire from the heat generated at the point of trouble; this is true, but the danger is more apparent than real. A dead ground, or one of above 1,000 ohms resistance would not be apt to give any trouble by fire. How many plants run along with grounds on both sides of the system? It would take time to develop a fire from this cause, and the testing of the largest isolated plant need not exceed two hours. At the end of the test the men would have located the ground and an incipient fire would run an exceedingly small chance of getting a good start. In any case the chance of danger can be avoided by making the artificial ground of high resistance and using a galvanometer, which, after all, is the better way. Right in here comes the subject of blowing out grounds. Don't; at least, don't make a practice of it. It is at best a heroic remedy. In any event the general location of the ground should be ascertained first and a careful watch kept for fire for some hours afterwards.

THE ELECTRO-MAGNET; or JOSEPH HENRY'S PLACE IN THE HISTORY OF THE ELECTRO-MAGNETIC

TELEGRAPH.-IX.

BY

Mary A. Henry

Henry's paper was in print.' In the wide circulation of Silliman's Journal it was carried abroad to place Henry at once among the scientific men of Europe. "At one bound" says Prof. Lovering "he came to the front. He had introduced his magnetic children into the world; had sent them forth to do their important work and how were they received? With surprise, nay with astonishment."

Mr. William B. Taylor says, "The magnetic 'spool' of fine wire, of a length tens and even hundreds of times that ever before employed for this purpose, was in itself a gift to science which really forms an epoch in the history of electro-magnetism. It is not too much to say that almost every advancement which has been made in this fruitful branch of physics since the time of Sturgeon's happy improvement, from the earliest researches of Faraday downward, has been directly indebted to Henry's magnet. By means of Henry's 'spool' the magnet almost at a bound was developed from a feeble childhood to a vigorous manhood. And so rapidly and generally was the new form introduced abroad among experimenters, few of whom had ever seen the paper of Henry, that probably very few indeed have been aware to whom they were really indebted for this familiar and powerful instrumentality." "

"But in addition to this large gift to science Henry (as we have seen) has the pre-eminent claim to popular gratitude of having first practically worked out the differing functions of two entirely different kinds of electro-magnet; the one surrounded with numerous coils of no great length, designated by him the quantity magnet, the other

1. It was printed Jan. 1st. 1831.

2 Henry's spool magnet appears to have been introduced into France by Pouillet in 1832. Nouveau Bulletin de Science: Publié par la Societé Philomatique de Paris, of 23 June 1832 p. 127. In Pouillets Éléments de Physique. 3rd Edition Vol. 1, p. 572 the date of this magnet is given as 1831-In the second Edition, 1832, no allusion to the magnet occurs.