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'. B and B' represent two direct current dynamos, and к and к' 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

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

FIG. 5.

permanently closed local circuits ww', including rheostats Rh2, Rh', 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 instruments, 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 ways in which this can be done are described in 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 ex

tent 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

behind that in the primary, which lag may be increased to a sufficient extent to practically obtain the same result as though two independent currents were used to energize the motor.

In another form, shown in Fig. 2, the arrangement of the parts is similar to that shown in Fig. 6, except that a selfinduction coil s, is introduced into one energizing circuit of the motor. The effect of thus increasing the self-induction in one of the circuits is to retard the phases of the current passing therein to a greater extent than in the other circuit, and in this way to secure the necessary difference in phase

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 the steamers, which will tow two consorts each, to put their barges far into these great slips, and then to follow head 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 electric hoists require only one man to a car. He travels 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.)

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.

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

ELECTRICAL ENGINEER, NY

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

piece has in it a drawbridge with 138 feet swing, and the circuit is maintained intact by means of a heavy Roebling submarine cable under the draw. The road also crosses bits of open sandy country and in one place cuts deep through a mile of wood. The illustrations show the strength of the construction, as in two of the picturesthat of the marshes and that of the trestle across Timber Creek to the Gloucester race track,-the train consists of one motor car and four trailers, having on board a densely packed crowd of 500 passengers. It need not be supposed, however, that the allurements of the racecourse alone explain such travel. Camden City has a normal population of 65,000; Gloucester, of 10,000; and the beautiful suburb of Woodbury, about 4,500; and as a matter of fact, the road is the only outlet for travel to the Atlantic section of South JerHence the necessity for heavy, solid work, and for such reinforcement as is shown in the cut of the bridge that has been cantilevered on top of the old construction, to secure proper stability.

The power plant for this interesting road comprises three boilers of Babcock & Wilcox make, of a total of 1,200 h. p. furnishing steam to three Westinghouse compound engines direct connected, 250 h. p. each, driving Westinghouse generators of equal capacity. The iron stack is 6 feet in diameter and stands 110 feet high. The power house is of

18 & 30 X 16 WESTINGHOUSE A. C. ENGINE DIRECT CONNECTED TO

NO. 9 WESTINGHOUSE D. C. GENERATOR

250 H.P. B. & W. BOILER

(2758 HEATING SURFACE)

& 30 X 16 WESTINGHOUSE 4. C. ENGINE

NO. 3 WESTINGHOUSE D. C. GENERATOR DIRECT CONNECTED TO

13 WALL

& 30 x 16 WESTINGHOUSE A. C. ENGINE

DIRECT CONNECTED TO

NO. 3 WESTINGHOUSE D. C. GENERATOR

-15-6

16-0

-15'6

-47-0

250 H. P. B. & W. BOJLER

(2758 HEATING SURFACE)

250 H. P. B. & W. BOILER

(2758 HEATING SURFACE)

3 DRAIN PIPE

3 DRAIN

Elec. Engineer

of its trestle work, which is, all told, no less than 3,730 feet long. There is one stretch that has as much as 2,480 feet in it, another of 900 and another of 350. The longest

brick and iron. A noteworthy feature is that this is in reality a combination plant, as the Gloucester Electric Light Co. has its station in a wing. This lighting plant

DYNAMO ROOM

TO SEWER

FROM RIVER