Some of these were very powerful; one in London at this time belonging to the Royal Society lifted one hundred pounds. These magnets were all permanent steel when endowed with magnetism retains it; not so soft iron. This bent bar of Sturgeon's was a magnet only while _____ the electricity was circulating through the wire around it; in this lay its advantage: it was a magnet, or not, at the will of man. It was not merely as a scientific fact that the world turned to it with such eagerness; it renewed an old hope that electricity might be made the messenger of man. The story of the electro-magnet is but a part of the story of the electric telegraph; we may not tell the one without reference to the other.

Sturgeon's Magnet.

We cannot go back far enough in the history of man to find a time when the idea of the distant communication of intelligence did not exist. In the earliest childhood of the race even, beacon fires proclaimed from hill to hill tidings of weal or woe. In those early days man looked up with dread to the lightning, thinking it "the eye-flash of an angry god," not dreaming that it was the manifestation of the agent which was to satisfy his long-cherished desire for distant communication with his fellowman, that the very genius of the storm was one day to serve as his

messenger.

It is interesting to know that Hauksbee of England in 1705 was the first to suspect the identity of lightning and electricity. He produced a thunder-storm in miniature by drawing a piece of amber swiftly through a woolen cloth. He says "a prodigious number of little cracklings were heard, every one of which produced a little flash of light. This light and crackling seem in some degree to represent thunder and lightning." As man learned in various ways, by the rubbing of amber and other substances, to excite electricity, and learned also the value of the force thus produced, also that the electrical influence could be transmitted through several hundred feet of wire, there came to him the conception that by the friction of his machines he might, as Aladdin by the rubbing of his lamp, summon the slave of his will which was to serve in the transmission of intelligence. The first attempts to use electricity for this purpose began in 1753. Who was the first to suggest the idea it seems difficult to determine; it was such a natural idea after the experimental results which had been obtained that it probably occurred to many minds at the same time, and it is only surprising that it was not conceived earlier. We may not here notice any one of the efforts in this line founded thus on frictional or static electricity; they form one of three distinct, although overlapping, eras in the history of the telegraph. They had a measure of success. They were very interesting from a scientific point of view and they served certain ends, but they did not give the telegraph to the world.

[By the telegraph I mean here that system or combination by which mechanical effects can be produced at great distances through seas, over continents-and I use the term in contradistinction to the many attempts towards this result, made at various times and in various places which if successful were so only in a limited degree, because the natural laws which control electrical action were undiscovered or unknown. Will the reader be so kind as to take especial notice of this remark; it is necessary for the proper understanding of my story.]

In Bologna, in the year 1753, a "religious youth of fourteen years was dreaming of church service, discouraged by his friends; while on the shores of Lake Como was playing a boy of eight;" these two were destined to make the discovery which was to form the second era in the history of the telegraph. In 1789, a dead frog's leg hanging upon a copper hook and kicking as though it were alive whenever the sportive wind blew it against an iron balcony-elec

tricity at work, in what seemed almost the enjoyment of a jest-revealed to Galvani that by chemical action, as well as by friction, the genius of the thunder-storm might be evoked. Volta followed with his "couronne de tasses" and thus came into being the Galvanic or Voltaic battery, bearing the names of both men. So general and profound was the interest excited that Napoleon Bonaparte invited Volta to Paris, witnessed his experiments with the instrument in the presence of the National Institute, and loaded him with decorations.

More eager now grew the hope of means of distant communication. The electricity of the machine, that is, the electricity produced by friction, had answered for this purpose only in a very limited degree; but this battery,-might not its long wires be extended indefinitely? Might not this current of Volta's, easily excited, easily set at rest, by the mere making or breaking of the contact of those same long wires, at last be the messenger so long desired? Of the many efforts in this direction, led in by Sommering of Munich, we may not speak. Could we follow their fortunes, now in one country, now in another, we would find that, however ingenious, sooner or later they all ended in the same difficulty, viz.: the failure of the electric force with increase in the extent of the conducting wire of the battery. It was but a question of time, or rather of distance; each new effort met the fate of its predecessors. For a while the electric force seemed to lend itself to this service, only to escape and laugh, as it were, at the efforts of the impotent creature, man, to bring it under restraint.

We turn now again to the electro-magnet. In a former article we tried to tell, in these pages, how the world found out that electricity could produce magnetism; step by step, from Oersted swaying his needle through the influence of the electric current, down to Ampere magnetizing needles in a glass case by means of electricity; we come back to 1824-25, to the bent iron bar in Sturgeon's cabinet and to the interest it excited. Then indeed the

A

OERSTED'S NEEDLE.

telegraph seemed a thing of the near future. There was not only the wonderful Voltaic battery, there was this magnet ready to respond to the will of man; could it not be made thus to respond at a distance? Surely the desire of the world would now be accomplished!

Barlow, a distinguished mathematician and engineer of England, essayed the practical experiment with the new instrument, while Europe waited, we might say, with bated breath, in confident expectation for the result. What was it? Again a disappointment. We will let Barlow speak for himself. "The details of the contrivance are SO obvious, the principles so well understood, that there is only this one question which could render the result doubtful. ful. Is there any diminution of effect by lengthening the conducting wire? I was therefore induced to make the trial, but found such a sensible diminution with only two hundred feet of wire as at once to convince me of the impracticability of the scheme." It could not be possible! The experiment was repeated in various ways, in the same year, 1825, and in the following year, but with like result; each experiment confirmed the reluctant conclusion that after all the brilliant discoveries which had excited such eager expectation, an electro-magnetic telegraph was an impossibility. Since Sturgeon's magnet, as well as Volta's battery, had failed, there appeared to be no means of obtaining sufficient electrical force to act at a distance.

Had the hope of the telegraph indeed ended, and in disappointment? For want of sufficient electric force the

telegraph is an impossibility; such seemed the verdict of the science of Europe, and with it we turn to America. Very brilliant was the old world of science, at that day represented in the line of physics by such men as Hansteen, studying the magnetism of the earth, Gay Lussac and Biot invading even the blue air in the search after the magnetic forces, the immortal Arago, the brilliant Ampere, we can only mention a few of the names which, -enrolled upon the lists of fame, have come down to us as household words. In America, to oppose that eminent array of veterans in this particular field of science there was only young Henry, in the Albany Academy.1 He dared to brave the electric force and demand of it greater energy. Mr. E. N. Dickerson says of him-"He was but a youth and ruddy and fair of countenance, armed only with a simple sling of his own construction and pebbles from the brook of nature, but he was equal to the trained warriors of maturer growth and superior armor, waging war against the Goliath that guarded the unexplored regions of nature's secrets; and like the great king of Israel, after the hunt of the battle was over, he came to be leader of the hosts who once had been tending only a few sheep in the wilderness."

THE REED INDUCTION SYSTEM OF TELEGRAPHY.

In the operation of telegraph lines the amount of energy required for the transmission of signals is of little account as compared with the importance of securing high speed. Thus, were it possible to increase the commercial capacity of an Atlantic cable ten times by the continuous use of one thousand horse power in current, instead of that of a few cells of battery, it would be an economical step on the company's part to substitute the power plant. The static capacity of long cable, under existing conditions, however, prevents the possibility of transmitting any large quantity of energy or of making variations travel with the desired speed.

Some of the most distinguished electricians of the day have endeavored to overcome this difficulty. About twenty years ago Mr. Edison proposed to do away with static capacity almost entirely by breaking up a long line into shorter circuits and employing induction coils; but his system was confined to a dot and space code, and the

FIGS. 1 AND 2.

action of the armature was unreliable. Prof. S. P. Thompson's method of transmitting a current the whole length of the line and then overcoming static retardation distributively, is still fresh in the minds of those who listened to his paper at the recent Electrical Congress or read the published reports of the proceedings; but while furnishing valuable food for

1. NOTE.-"On the shoulders of young Henry has fallen the mantle of Franklin" were the words of Sir David Brewster. It is true Cox had suggested a chemical telegraph and Hare made many improvements in galvanic apparatus, but no representative of Franklin, in a series of connected experiments, had entered the field of electric sclence in America, until Henry began his researches. 2. See THE ELECTRICAL ENGINEER, Aug. 80, 1892.

thought, and much that was theoretically novel and valuable it seems to be open to several practical and mechanical objections. Other inventors have devised ingenious systems to overcome the difficulty but none has yet proved useful in practice.

Mr. C. J. Reed, of Philadelphia, has recently worked out a method embodying principles which seem to meet the requirements of the case and in a manner distinctly novel and to all appearances practically available. In his system he employs a true alternating current successively induced in separate metallic circuits which may be entirely insulated from one another. This enables him to use high X

FIGS. 3 AND 4.

Y

At

electromotive force and transmit large quantities of energy and reduce the static retardation practically to zero. the same time almost any receiving instrument may be used, as it is only necessary to provide it with a local means of maintaining the temporary effects of an inductive impulse until the reverse inductive impulse arrives to destroy it.

the form of cable employed. In Fig. 1, w and w' are inIn the accompanying illustrations, Figs. 1 and 2 show sulated conductors lying side by side throughout the entire distance between two stations, the conductor w being connected at each end of the line directly to the terminals of the converters B and to the outer metallic coating c, while the conductor w' is connected at both ends directly to the metallic casing. w w' are insulated branch conductors located at stated distances apart, those on the lower side of the drawings connecting the conductor w directly with the outer metallic casing c while those on the upper side and intermediate between those described connect the conductor w' with the metallic casing. I is a metallic sheathing of iron wound in layers around two parallel conductors w and w', constituting an inductive field around them.

When an impulse is set up through the primary of, say, the left hand converter B, a secondary or induced impulse will be set up through the conductor w and the first one of the short conductors w returning through the outer casing c, thus inducing in the first section of the conductor w' an impulse which in turn induces in the next succeeding section a corresponding induced impulse; and so on through the series until the final impulse is effected through the conductor w and its connections through the coil of the right hand converter в which in turn induces the working impulse in the receiving instrument.

In another form shown in Fig. 2 the continuous conductors are replaced by a series of short conductors w w, the ends of which project past each other in alternating order and are connected to the outer casing c, the parallel or inductive portions of the circuits being surrounded with iron wire, as shown at A, while the intermediate portions between these casings form the conducting parts.

In Fig. 3 are shown two main telegraph stations X and Y joined together by an intervening cable consisting of an internal conductor L insulated from a surrounding conduct

ing shield L, the two portions constituting the direct and return conductors and including in their circuits at the opposite stations the secondary coils of two converters c c, and the similar coils of an intermediate converter c'. в and B' represent two direct current dynamos, and к and K' the transmitting or signaling keys at the transmitting stations, connected in local circuits with the generators through the primaries of the converters c and c', rheostats Rh and Rh' and conductors w3 and w*.

s and s' are the receiving instruments connected through

conductors w and w' with additional coils on the converters

cc. The armature levers A and A' may be permanently magnetized, or they may be energized by coils included in

permanently closed local circuits ww', including rheostats Rh2, Rh3, so that the influence of the retractile springs t will prevent the armature from being drawn forward under normal conditions (Fig. 4).

When the operator at station X closes the key K an inductive impulse will be set up in the local circuit w3 of the converter c, which sets up two individual secondary impulses, one in the main line L L' running to the distant station Y and the other in the receiving instrument s, the magnetic effect of which is such as to momentarily increase the pull on the armature a sufficiently to enable the armature lever T to overcome the influence of the spring t and draw it into the forward position shown. In like manner the impulse sent to the distant station sets up in the secondary of the converter c' an impulse which, acting through the coils c, secondary circuit w' and coils of s' causes the armature a' to be drawn into its lower position as shown. Both armatures will therefore remain in their lower position by virtue of their own magnetism after these impulses cause them to be brought down until the key K is opened, when like impulses in a reverse direction cause both armatures to be repelled. Hence for simple inductive impulses, signals may be transmitted, such as the Morse code, in which the elements of the characters are of varying lengths.

In Fig. 5 is illustrated an apparatus for use in cable telegraphy or on long land lines, which consists of a series of converters c c' located in the body of the cable, the outer surface being of metal constituting a common return circuit for the primaries of all the converters. T' represents a test line embedded in the cable for detecting breaks.

It will be seen also that the inventor is enabled to insulate all receivers from the main line by several inches of air space and interpose a grounded piece of sheet metal of any size required to prevent the possibility of lightning reaching the receiver. It may also be adapted to telegraphy between moving trains with the same facility as between fixed stations.

The system does not involve the use of a new code or the slightest change in the present one and entails very little expense in changing from the present Morse system, as the same instruments are employed with only a modification of the armature. Another valuable feature is the

possibility of multiplying the messages sent by creating similar impulses on a number of lines radiating from the same point. Mr. Reed claims that with his system several hundred words a minute might be sent from New York with an automatic transmitter, and simultaneously received in all the great capitals of the world.

A FRANCHISE has been granted to I. Sparks for operating a local telephone exchange in Santa Fe and vicinity. The poles are erected, and the system will soon be in operation.

TESLA MOTORS OPERATED FROM SINGLE PHASE TWO-WIRE ALTERNATING CIRCUITS.

THOSE who have followed Mr. Tesla's work in alternating motors will recall that in 1888 he first drew public attention to his new multiphase system of operating alternating current motors, in a paper read before the American Institute of Electrical Engineers, in which he laid down the principles which have since been practically apbered, each motor contains two or more independent enerplied in many ways. In this system, it will be rememrents, having in each circuit such a difference of phase that gizing circuits through which are passed alternating curby their combined or resultant action they produce a rotary progression of the poles or points of maximum magnetic effect of the motor and thereby maintain the rotation of the armature.

A multiphase system of this kind, however, requires at least three wires for its successful operation, to convey the currents differing in phase, and Mr. Tesla, therefore, early set about to devise means for operating phase motors from the ordinary single-phase alternating circuit, by creating the difference of phase locally at and in the motor. The various in which this can be done are described in ways two patents just granted to Mr. Tesla, which are of special interest at this time.

In all the methods described below, the fundamental idea involved is to pass a single alternating current through both of the energizing circuits of the motor, and to retard the phase of the current in one circuit to a greater or less extent than in the other. The distribution of current between the two motor circuits is effected either by induction or by derivation.

The diagram Fig. 1 shows a motor with two energizing circuits, c and D. One of these circuits, c, is connected directly with the line circuit, while the other set of coils D, is connected up in the secondary circuit of a transformer T. The primary coil P of this transformer, is connected to the line circuit. The alternations of current in the line tend to establish in their passage through the coils c, a polarity opposed to that set up in the coils D, and if the currents in the two sets of coils coincided in their phases, no rotary effect would be produced. But the secondary current developed in the coil p' of the transformer, will lag

ing effects produced. For example, a reduction of the resistance in one circuit imparts to the motor rotation in one direction while a reduction of the resistance in the other circuit will produce a rotation in the opposite direction. By means of the two resistances, therefore, capable of variation or of being bodily withdrawn from or inserted in the circuits by simple means, rotation of the motor is secured.

In Fig. 4 a self-induction coil s is included in one of the motor circuits and a dead resistance R in the other. The

increased self-induction in one circuit thus produced acts to increase the difference of phase between the current in that motor circuit and the unretarded current in the line circuit. On the other hand, the introduction of the dead resistance in the other motor circuit reduces the retardation and brings the phases of the current in it more closely in accord with those of the unretarded current, thus producing a correspondingly greater difference of phase between the two currents in the energizing circuits C and D.

rotary effect will be produced by the passage through them of an alternating current from the line. But if one of the motor circuits, as c, be varied or modified by the introduction of a dead resistance R, the self-induction of that circuit or branch is reduced, and the phases of current therein retarded to a correspondingly less extent. The relative degrees of retardation of the phases of the current in the two motor circuits with respect to those of the unretarded current in the circuit в thus produced, will set up a rotation of the motor.

Finally we may mention another type in which one set of energizing coils is of finer wire than the other or has a greater number of convolutions; or each circuit may contain the same number of convolutions, but composed of different conductors, as, for instance, one of copper, and the other of German silver.

Mr. Tesla has devised still other methods for accomplishing the same purpose, but those described will give a fair idea of the wonderful flexibility of the system.

ELECTRIC HOISTS FOR WHALEBACKS.

A NEW departure is promised in connection with the proposed new ore docks for the whalebacks at Conneaut, O., says the Evening Wisconsin. Permanent bridges will span slips 100 ft. wide for the operation of electric hoisting machines. These bridges will be high enough to clear the decks of the whaleback barges by 30 ft. The design is for barges far into these great slips, and then to follow head the steamers, which will tow two consorts each, to put their in, the three passing under the trestle bridges, except that the stern of the steamer, with the stack, will be outside the outer trestle. The cars will then run directly over the hatches, dumping the ore on either side of the slip. The He travels electric hoists require only one man to a car. with the bucket, and dispenses with the signal men and extra engineers and firemen required by the steam hoists. The same power that propels the machinery generates light, so that the stock piles and the holds of the boats can be illuminated and the work carried on by night as well as by day. The method was fully illustrated and described

in THE ELECTRICAL ENGINEER of Dec. 23, 1891.

PENNY-IN-THE-SLOT ELECTRIC LIGHTS.

THE penny-in-the-slot electric lamps have come into use on the London underground railways this week, says the English Western Mail. Trusting to memory, I will say it is two years since the first experimental lamps were put on a few trains. Since then arrangements have been made to fit the lamps to all the trains and the work is now complete. There are four lamps in each compartment. If you want to read, and the ordinary light is insufficient (that is a dead certainty), you put a penny in the slot and obtain an electric light, which lasts you half an hour. If you want more you have to put in another penny. The lamps are conveniently placed at the back of the seat so as to throw the light on the book or paper. They were in immense demand at the outset. Every one wanted a pennyworth of electric light, and I believe people used the trains on purpose to try the lamps. (The apparatus can be seen at the office of THE ELECTRICAL ENGINEER.)

C

R

FIGS. 5 AND 6.

In Fig. 5, two self-induction coils are shown, one in each motor or energizing circuit. One of these coils is much smaller than the other and has less self-induction or counter-E. M. F. than the other, so that the phases of current will be retarded to a less extent than in the other.

In Fig. 6 the two energizing circuits of the motor are shown connected in multiple arc to the line circuit and in one of these circuits is a resistance R. Assuming the two motor circuits to have the same degree of self-induction no

ELECTRIC LIGHTS IN HARTFORD, CONN.

GREAT improvement is expected in the electric street lighting at Hartford, Conn., where President Dunham of the Hartford Electric Light Co. is adopting the Howard incandescent arc system, by which the arc is inclosed in a glass envelope adding enormously to the life of the carbons, giving absolute freedom from flying sparks, and reducing to a minimum the labor of trimming. The Royal Arc Electric Co. of New York, controlling the Howard patents and apparatus, has organized a sub-company in Connecticut, which is to furnish the necessary outfit.

CESTER AND WOODBURY.

NEW JERSEY along its eastward front is so thorough a blending of sea and land that one is always a little in wonder why the Dutchmen who settled on rock-ribbed Manhattan did not endeavor rather to make their home among

too good for other people to neglect, and in these later times, with the aid of the electric railway, the outermost of her shifting sands are being converted into profitable farms and bright summer resorts. Where a dyke would have been thrown up, the modern equivalent is a railway embankment with a trolley line on top of it.

the sand dunes and mud banks that stretch south from the Kill von Kull to Cape May. Probably they were rather weary of their job of canal digging and pile driving in old Europe and found more pleasure in a change of occu

AT THE DRAW, TIMBER CREEK.

Reference has already been made in THE ELECTRICAL ENGINEER to some of these coast roads in New Jersey, and the coming year will witness several additions to the number. But perhaps the most striking of all is one about which least has yet been said, and as it is very nearly all in operation now, a description will be timely. While it is not exactly a coast road, it is only bald accuracy to speak of it as amphibious, as wallowing in salt water where fresh is not handy. This road is the Camden, Gloucester and Woodbury Railway, built for the company of that name by the Complete Electric Construction Co., of New York city. The three places that give the road its name may be regarded as suburbs of Philadelphia, but have other claims to distinction and liveliness, particularly Gloucester, to whose race track hie the Quaker youth and whose planked shad is a dainty that men have been known to travel