=

2

But R. (R+L ∞1 — L ∞); hence (R' + L'∞1) < (L∞ + 0.118)' or L > 20.4. Hence L must exceed 0.0204 henrys per mile.

From the formula (9) we see that L ∞ varies from to 2.2 as R. decreases in value from 0.118 to 0.059. Therefore the value L ∞ = 20.4 is accurate enough for all purposes. A single approximation, however, determines its value far closer than 1 per cent. at 20.5. Therefore we see that for this particular rate of alternation the current at the distant end could be increased by an increase in the retardation factor. The abruptness of the curve at its maximum point may be shown by a simple calculation for this frequency, 4. e., 160 periods per second.

We see from this that upon such a line as that under discussion, the retardation factor varies directly with the capacity per unit of length, with the square of the resistance per unit of length, and with the square of the length of the circuit. The interesting fact is that it is independent of the rate of alternation. Up to a certain point the factor L is influenced by the rate, increasing with an increase in the frequency as seen by equation (10). But when the rate approaches 100 or more alternations per second upon a line of this length its influence upon the value of L for a maximum I disappears. As all important telephonic rates exceed 100 vibrations per second, the value of L which renders 160 periods per second a maximum will render them all a maximum.

An interesting point is the determination of the length of line upon which the maximum current is naturally reached; that is the length corresponding to a value of L of .00161 henry per mile.

epl

ep1

is a maximum. Remembering that the fraction

1

pl

for a maximum, or log Co

Where R, as before, represents R+L — Lw. Thus we see that under certain conditions the value of the current at the distant end of the line is actually increased by the capacity of the circuit. The value of C to give a maximum current at the distant end varies inversely with the square of the length of circuit and as some power of L and determined by the resistance in the factor ( √R2+L2 ∞2 - L ∞). As an increase in L decreases R, C varies directly with some power of L.

8

=

It must be borne in mind that this and the other formulæ apply only to cases in which the wave length is not greater than twice the length of the circuit. Thus from equation (12) it would appear possible to secure a greater current at the distant end of a line devoid of all retardation if it contained a small amount of capacity rather than no capacity at all. For when L = 0, R = R .0009 and C = But on substituting these valᎨ Ꭱ 106 ues in (7) we find x = 6,800 miles which is more than twice the circuit length. As C varies inversely with the square of the length and inversely with ∞ in formula (12) when L 0, and as the wave length varies inversely as the square root of C and ∞ when L = 0, we see that no values of 7 and ∞ can render (12) applicable when L = 0. This can only mean that when L = 0, C must be zero to render I a maximum.

SALADIN'S ELECTRIC FURNACE.

A PAPER has been read by Mons. Saladin, before the Chemical Society of Paris, on his improved electrical furThis furnace appears to differ in principle from others, as it is based upon the electrical cautery. A platinum spiral rendered incandescent by means of a continuous or alternating current of electricity is placed in a vessel of refractory material, and the whole is enclosed in a cast-steel case. It is possible to act upon substances placed in this furnace by means of high pressure, as well as high temperature. A side opening in the case communicates with a pump and manometer, and admits of the pressure being increased to 1,000 atmospheres. The range of temperature available is 1,500°-1,800° C., and this is measured by a platinum-rhodium couple, arranged according to Le Chatelier. Mons. Saladin claims that by means of this furnace it becomes possible to fuse metals under high pressure, and while maintaining any desired pressure to cool the molten metal as slowly as is deemed desirable, this cooling being governed by regulating the current. At present we understand that this furnace is being used in obtaining experimentally the reproduction of minerals from elementary matters, the idea being to imitate the probable conditions under which they have been naturally formed.

THE WESTINGHOUSE COMPANY AND THE NIAGARA CONTRACT.

WE

E print elsewhere in this issue an important communication from Mr. L. B. Stillwell, on behalf of the Westinghouse Co., which sheds a strong side light on the information embodied in Prof. Forbes' paper on the electrical features of the Niagara transmission plant. This communication, taken in connection with Prof. Forbes' own statements, would make it appear that so far as essential features are concerned, the promoters of the Niagara scheme deemed it wise to accept the advice of experienced constructors in preference to that of their consulting electrical engineer. And this brings us back to the old question of the relation between these two frequently antago nistic elements. The consulting electrical engineer's services have from the very outset been little availed of in this country, purchasers of electrical plants having in the large majority of cases left matters entirely in the hands of the contracting companies, which practice has, it must be admitted, given rise to but few conflicts. In the case of the work at Niagara, it would appear that the consulting electrical engineer, instead of confining himself to laying down the conditions and leaving to the contractors to devise the best methods of carrying out the specifications, actually entered into competition with them, with the result that might have been foreseen. According to Mr. Stillwell it would also seem that while the engineers of the Westinghouse Co., are in accord with Prof. Forbes on the selection of the methods adopted, they differ from him radically in the assumptions and reasoning which led them to advocate the final plans adopted.

It would be interesting to know the details of these differences and it is to be hoped that the electrical profession will not be kept in ignorance of them. For this reason it is perhaps a pity that Prof. Forbes' paper could not have been read and discussed on this side of the water also. Probably an early opportunity may be afforded by the Institute for such a timely discussion.

THE TESLA ELECTRICAL OSCILLATOR. WHILE Mr. Tesla has until the last year or two confined himself to purely electrical work, his most recent labors have been devoted to the solution of a mechanical problem intimately connected with the generation of electric currents, the outcome being his electrical oscillators, of which we describe two additional types in this week's issue. Aside from the numerous possibilities in other fields it would seem that if the "oscillator" fulfills the expectations of its inventor, it is destined to create little short of a revolution in our present methods of power generation and distribution. It must be confessed that in spite of the numerous obvious cases in which the application of motors to the driving of machines and line shafting would prove a gain over the present methods, and despite even the successful working of such plants, the conservative factory owner and machinist still looks with a doubtful glance at these innovations of the last ten years. But, if, he will Mr. Tesla claims, he be able to furnish electric current by means of his oscillator,

as

39

40

at anything like one half the cost for fuel now required and with much simpler apparatus, the aspect becomes quite a

different one. Such an accomplishment would immediately appeal to every power user and would at once determine the direction of future methods of local power transmission. Indeed it might not be inapt to inquire here also into the probable effect of such an achievement on long distance electrical transmission. With the potentials which have been practically handled up to date, the size of conductors required has not permitted of the extension of power transmission plants utilizing water power, to the distances hoped for, although we note small but constant gains in this respect. With the initial source of energy in the shape of fuel reduced to one half the present cost, it would indeed require an exceptional set of conditions such for example, as those existing at Niagara or in regions far remote from fuel supply to make the utilization of water-powers worth considering for any considerable distance from the fall. Already the cost of water power even locally distributed has in numerous conspicuous instances proved less economical in competition with modern steam engines and a still further improvement in the latter added to the benefits to be derived from electric motors must still further tend to decrease the comparative margin of economy with water power. It seems strange indeed that a power available on the spot should not be able to compete in economy with another form of energy hauled frequently for a distance of hundreds of miles, but experience bears out the conclusions just stated. While the above remarks refer merely to power distribution they are equally applicable to the question of electric lighting and current distribution in general. From Mr. Tesla's observations before the recent meeting of the New York Electrical Society (see THE ELECTRICAL ENGINEER, Dec. 6 and 13, 1893) we infer that he has so far gone into the study of the methods he advocates that we shall not have to wait long for their practical realization.

ELECTRICITY AND THE STATE.

The reference to electricity in no less than three of the annual State papers of New York serves to indicate the important position assumed by this later source of energy. In the reports made to the Legislature by Gov. Flower, State Engineer Schenck and Superintendent of Public Works Hannan, reference is made to the contemplated employment of electricity as a motive power on the Erie Canal. The utterances of Mr. Schenck show him to be still somewhat skeptical as to the economy of the electric method as compared with the steam canal boat, the independence of which still appears to him as a most valuable feature. Judging from his other remarks it is evident that he has never heard of the dynamotor or motor transformer, nor of the work now actually being done by alternate current motors. On the other hand we are glad to note the intelligent grasp of the subject apparent in the brief reference to it contained in Mr. Hannan's report. This gentleman estimates that with a steam electric plant serving a stretch of 50 miles and operating 210 days in the year canal boats can be propelled for 10 cents per mile per boat, while still others estimate it at nearly one half this figure. If during the season when the canal is closed the power could be utilized in other ways the cost would be still further reduced. Mr. Hannan concludes from all this that the

claims to consideration for electric motive power on the canal are extremely well founded.

In the message of Governor Flower we note also a reference to the alleged increase of fires due to defective electric wiring, and a suggestion that persons installing such work be licensed by a competent board certifying to their fitness to carry it out properly. There is much to be commended in this plan which was for some time in operation in New England, but has unfortunately been allowed to lapse. Perhaps the trades unions themselves might find the easiest solution of this problem by allowing no one into their ranks who could not pass a rigid examination on wiring work. The statement that in the city of New York there are four times the number of fires that there are in the principal cities of Europe, accompanied by four times the destruction of property, may be true, but to cite it in the present connection without further qualification and without giving any figures or details whatever seems hardly fair, We know as a matter of fact that the actual figures on fires claimed to be of electrical origin do not in the least warrant any such assertion or inference and we are sorry indeed to see so unguarded a statement in a Governor's annual message. Last week we referred to a case within our personal knowledge where the insurance rate had been advanced nearly five fold-from 15 cents per $100 to 70. Inquiry elicits the fact that apartment buildings over a certain height have been re-rated on that basis. As we said last week, electricity has nothing to do with the case.

BI-METALLIC WIRES IN TELEPHONY.

EVER and anon the electrical public is brought face to face with statements and facts so at variance with past experience that they force themselves upon its attention and cause it to pause and ponder. The most recent example of a surprise of this nature is the discovery of the extraordinary properties of a composite wire for the transmission of telephonic currents and indeed for alternating currents in general. If we are to believe the statements printed on another page, from Mr. Wm. H. Eckert, whose long telegraphic and telephonic experience entitles his opinion to some weight, a composite wire embodies within itself properties which serve to overcome retardation whether due to electro-magnetic impedance or electro-static charge while at the same time it makes current largely independent of insulation. A result differing so widely from what we have been accustomed to deem as an inevitable accompaniments of all conductors will of course be accepted with great caution, but as the inventor bases his statements on actual experiments we must await further developments on this decidely interesting innovation with no small hopefulness.

An Injunction Against a “Gas" Lamp.

BI-METALLIC WIRES FOR TELEPHONE
CONDUCTORS.

OUR readers may recall the fact that early in 1883, the Postal Telegraph Co. in extending its lines to the West employed a composite wire consisting of a steel core upon which a thick layer of copper was deposited. This conductor had a tensile strength greatly exceeding that of any similar line theretofore employed, and, in addition, had a much greater conductivity, its resistance between Chicago and New York being only 1,552 ohms, or a little over 14 ohms per mile. The results obtained with this wire telegraphically were so good that it at once suggested the possibility of employing the line for telephonic transmission as well, and among those who tried experiments on it were Van Rysselberghe, Baxter and others. Although only a single circuit grounded at both ends was employed, the articulation was distinct with all kinds of transmitters, and between New York and Cleveland the ordinary Bell magneto receiver used as a transmitter was sufficient to carry on conversation. These good results were attributed generally to the high conductivity and excellent insulation of the wire, and subsequent long distance telephone work was carried out on the basis of securing similar advantageous conditions.

Among those who had an opportunity of witnessing these experiments was Mr. Wm. H. Eckert, at that time general manager of the Metropolitan Telegraph and Telephone Co., of New York. When the Long Distance lines between New York and Philadelphia were erected, the difficulty at first experienced in obtaining distinct articulation, before the proper transposition of the wires was effected, impressed itself strongly upon Mr. Eckert, in whose mind the experiments with the Postal Telegraph wire were still fresh. After much thought devoted to the subject Mr. Eckert arrived at the conclusion that neither the greater conductivity nor the higher insulation of the Postal wire accounted for the excellent results obtained with it but that its properties were due due to the dual nature of its composition. Subsequent experiments appear to have fully convinced him of the correctness of this view, and in a pateut just issued to him we find a

number of most interesting statements relating to his discovery.

Mr. Eckert holds that telephonic transmission, or rapidly alternating currents in general, may be more perfectly effected upon a bimetallic conductor, such as steel and copper in equal parts, than upon a conductor of one material such as copper; and with the advantage that such transmission may be effected upon a circuit consisting of a single composite wire and an earth return as perfectly as though two copper wires, each of equal conductivity, were arranged in a closed metallic circuit. In other words, he finds that a single bimetallic conductor joining two distant points is a more perfect medium for telephonic transmission and for conveying generally rapidly alternating currents than are two copper conductors, each of a resistance equal to that of the bimetallic wire; and that from this fact the two conductors necessary to form a single metallic circuit may be replaced by a single wire costing little, if any, more than one-half of a copper metallic circuit. He also claims that less insulation is needed to protect a bimetallic wire than is necessary for copper or other single substance conductors, in the transmission of rapidly alternating currents, and that from this fact not only the expense of constructing cables, whether ærial, underground or submarine, may be greatly reduced but more wires may be placed within a cable than could be done if the usual thickness of insulation were used. Moreover, for the transmission of alternating currents, wires of smaller conductivity according to the ordinary resistance measurements, may be used than is possible if they were constructed of copper, iron or other single metal.

Among the experiments made by Mr. Eckert to demonstrate the practical nature of his discovery is one in which à composite bare wire of No. 20 B. & S. gauge was stretched on the ground for a distance of 10 miles and grounded at both ends. The articulation left nothing to be desired.

Mr. Eckert does not vouchsafe any theory to account for the remarkable properties which he attributes to the composite wire, but contents himself thus far with the statement of the facts as he has found them to exist.

GOVERNOR FLOWER ON ELECTRICAL CANAL PROPULSION.

In his annual message to the New York State Legislature, Governor Flower_makes the following reference to the use of electricity on the Erie Canal as one of the means of deriving more benefit from that great waterway :

"The most practical suggestions are contained in plans for increasing the tonnage of the Erie Canal. One of these plans has been in process of construction during the last seven years. It consists in lengthening the locks so as to permit two boats to pass through at the same time, thereby saving expense and time of transportation. Under this policy all but four of the locks which it is feasible to lengthen, in the opinion of the Superintendent of Public Works, have been so lengthenened. The cost has been about $3,000,000 thus far. The results have been disappointing, for the tonnage of the canals has diminished instead of increased. The lengthening of the remaining four locks will not change the situation materially, for it requires on the average about three minutes to lock a boat, so that the time saved between Buffalo and Albany by lengthening the remaining locks would be less than half an hour.

"Another plan proposed in connection with the lengthening of the locks is the deepening of the canal and the raising of its banks, so as to enable boats of larger capacity to be used. The deepening of the canal would necessitate the rebuilding of all its structures -an enormously expensive undertaking; the raising of the banks, however, would be quite feasible as a means of securing greater depth of water. Something in this direction should undoubtely be done when the present capacity of the canal proves insufficient, and at present provision should be made for the prompt removal

of all accumulations in the bottom of the canal, so that its full depth may be enjoyed.

"It has seemed to me, however, that the most practical plan for immediately increasing the tonnage of the Erie Canal is that which would supply a speedier and more economical motive power. Mules and horses now propel canal-boats at a rate of about two miles an hour, while steam sends them along at the rate of about three miles. The banks of the canal will stand a speed of about four miles an hour. It seems to me, after personal observation of present methods, that electricity might be applied as a motive power with a considerable saving in cost and a considerable increase in speed. Experiments in this direction were authorized by the last Legislature upon my recommendation, and seem to have demonstrated clearly the feasibility of using electricity as a motive power on the canals, The only question still to be determined is that of cost, and the estimates are quite favorable to a considerable reduction from the cost of propulsion by steam. Just how much of a reduction could be obtained it is of course impossible to say definitely, but very conservative estimates make the saving in cost of transportation at least 25 per cent., and the increase in speed at least 30 per cent. The advantage of electricity over mule or horse power would be much greater. If these results could be attained the benefit to the canal would be immediately greater than the benefit which would flow from all the proposed enlargements, and need not cost the state a penny. Boatmen could make many more trips in a season, fewer employés would be needed on each boat, no money would be required for horses and mules, the large space occupied by steamboiler and engine would be saved for freight, and danger from fire or explosion would be avoided. At the same time the increased tonnage and business of the canal would provide more

employment and more remunerative occupation for boatmen. Other advantages readily suggest themselves. It should be clearly understood, moreover, that the adoption of electricity as a motive power does not mean the abandonment of horse, mule, or steam power if boat-owners prefer to have their boats propelled by these powers. The idea is that whether the state furnishes the electric power from its own plant, or whether individuals or corporations furnish it under contract, there will be no compulsion to use it, but the endeavor will be to supply it at such a low cost to boatmen that they will find it advantageous to apply it to their boats in the interest of economy.

"This plan need not interfere, either, with any proper enlargement or deepening of the canal. Instead, if the plan is found to operate satisfactorily, the next logical and necessary step would probably be to so improve the canal as to enable the use of larger boats. But for the present I am quite convinced that the proper course is to give electric propulsion a fair trial, and if it accomplishes what is claimed for it, a new era of activity and prosperity should begin for our canals. Grain has been carried during the last season from Chicago to Buffalo for as low as one cent a bushel; boatmen can carry it profitably at two cents a bushel. If by cheaper and quicker propulsion the cost from Buffalo to New York by way of the Erie Canal can be reduced to three cents a bushel, as is reasonable to suppose, there is no other carrying route that can successfully compete with it, and a continuance of New York's supremacy is assured. Moreover, the harnessing of the tremendous water torrent of Niagara to the wheels of industry will furnish the cities of Buffalo and Rochester and all western New York with the cheapest power for manufacturing in the United States. We may look forward to the time when the great flour mills of the world will be located there, for the cheapness of power would more than compensate for the cost of transportation of grain from the fields of the Northwest. So with other manufactories. Then, more than ever, will be needed cheap transportation through the State. To day the Erie Canal does not carry one-half its capacity. Reduce the cost of transportation and increase the speed and the tonnage will increase, and when the tonnage increases then will be the proper time to seriously consider expensive schemes of enlargement.

"The essential point in arranging for the application of electric propulsion on the canals is that the power should be furnished at the lowest possible cost, and any construction of state works for this purpose or any contract with individuals or corporations for supplying power to the boatmen should be hedged about with abundant safeguards for the protection of the public interests."

THE NEW YORK STATE ENGINEER ON CANAL TROLLEYS.

STATE ENGINEER SCHENCK, in his annual report to the New York State Legislature has a very interesting discussion of the application of electricity to the canals of the State. It is as follows:

Of the several schemes of improvement advocated by the friends of the Erie Canal, one of the most feasible, when its comparatively small cost is taken into consideration, is that known as the Seymour plan, by which it is proposed to deepen the canal to a depth of nine feet of water, by raising the banks one foot and by excavating the bottom one foot, except through locks and over aqueducts and culverts, and lengthening the locks so as to permit the passage of double headers.

I have plans for an enlarged canal, 100 feet in width and 12 feet deep, capable of bearing barges 250 feet in length and 25 feet broad on beam, with 10 feet draught of water, and of the lowest possible height above water, so that the greater part of the bridges crossing it could be fixed structures, instead of movable ones. The cost should not exceed $25,000,000.

I recommend that a commission be appointed, whose duty it shall be to examine into this matter and to report its conclusions to the Legislature at the earliest time practicable.

While there are some minor difficulties to be overcome in the application of the trolley system to canal navigation, such as the holding of the boat while not in motion or moving at a low rate of speed and exposed to the action of high winds, in proper posi tion to secure easy contact of the trolley with the wire carrying the current, the devising of means by which boats traveling in the same direction at different rates can pass each other, or by which boats can be brought up to or taken away from a dock, etc., I think none of these difficulties are so serious but that they will be surmounted by the inventive genius of our people. The main question is a purely economic one, and the success or failure of investigations now in progress will be decided by the answer to the question, Can the electric power be furnished to each propeller at less cost than that of steam?

Two trolley methods have been suggested by which to reach the desired end-one by establishing power houses along the line of the canal at such distances apart as may be found economical or desirable, and in these power houses, by the use of fuel to to generate steam, transform this steam power into electric power, transmit this electric power by wire between these power houses,

and by means of a trolley wire communicate it to motors in canal boats acting to turn a screw wheel. The other is the generating of electricity in large quantities by means of water power at some point or points where nature has provided the means, and then transmitting the current over long distances by wire.

From the figures furnished by the Albany Electric Railway, I conclude that if, as was shown me, we succeeded in developing in an engine cylinder one horse power per hour with two pounds of coal, we would have a consumption of coal to obtain one horse power per hour applied at a distance of eight miles from power house of from four and a half to four and three-quarters pounds. This is in excess of the amount of the coal consumed by canal steamers, to say nothing of difference in first cost of plant required.

The method of generating electricity in large quantities at points where large water powers exist and thence transmitting it by wire over long distances is the one which, to my mind, contains the greatest promise of success. In order, however, to economically transmit the large quantities required, the current in the feed wire must pass at very high voltage, and in order to secure safety that in the trolley wire must pass at a low voltage. While it is perfectly feasible to transform an alternating current from a high to a low and from a low to a high voltage, unfortunately no means have yet been found for thus dealing with a continuous current, and it is the continuous current alone that has as yet been successfully applied to the operation of motors.

Upon the solution of one or the other of these difficulties, and upon the devising of means to more economically and perfectly insulate the feed wires, depends, in my opinion, the success or failure of the efforts now being made in this direction.

I am advised that there has been developed by a corporation operating at Niagara Falls a water power yielding on the American side 200,000 horse power per hour (sic), and on the Canadian side 120,000 horse power per hour, which, they state, could be disposed of at a profit to the corporation at the price of $4 horse power per annum, measured on wires at Niagara Falls, if sold in its entirety. In considering this question it must be remembered that the steamboat has and must continue to hold an advantage over a trolleypropelled electrical boat in_that she is independent of outside aid in navigating the Hudson River.

I commend this subject to your careful consideration and hope that you will adopt the necessary legislation to secure the continuance of the investigations and experiments necessary to reach a conclusion.

FROM NEW YORK TO PHILADELPHIA BY ELECTRIC RAILWAY. WHAT will be, when completed, the longest electric railway in existence is about to be built between New York and Philadelphia by way of Newark, Paterson and Trenton. The originator of the enterprise is Mr. Joseph H. Reall, of Bloomfield, Ñ. J., who is well known as a railway builder, and the New Jersey Railway Company has been formed to carry out his plan.

There is already an electric railway projected along the banks of the Delaware from Philadelphia to Trenton. Beginning where this ceases, Mr. Reall's system leaves the latter town and passes through Lawrenceville, Princeton, Kingston, Rocky Hill and East Millstone to Bound Brook, whence branches lead to Somerville and Raritan on the west and New Brunswick on the east. Passing north from Bound Brook the line runs northeast to Westfield, passing through Dunellen, Plainfield and Fanwood. From Westfield a branch will run to Rahway, Elizabeth, Woodbridge, Boynton Beach and Perth Amboy, forming a short line from North Jersey and Eastern Pennsylvania to the seashore.

The line continues northeast from Westfield passing through Springfield, Millburn, Wyoming, South Orange, Orange, West Orange, East Orange, Bloomfield, Montclair, and thence to Paterson, with a branch from Millburn to Irvington and Newark on the east and to Morristown on the west. Another branch extends from Montclair to Caldwell. Altogether, the system comprises more than one hundred miles of track. From Newark to Jersey City there is now a well equipped electric road in actual operation.

The entire line has been surveyed, the right of way has been secured and the necessary franchises are assured. The people from one end of the line to the other are highly in favor of its construction, and the leading and most influential men in the different towns and the intermediate country through which the road passes are actively interested in and warm supporters of the enterprise. The road will be laid with seventy and ninety pound steel rails and equipped with thirty four foot, double motor cars of thirty horse power each. The speed will be eight to ten miles per hour in cities and towns, and twenty-five to thirty miles in the country. The cars will be run on from fifteen minutes to one hour headway, according to the amount of traffic, and where the trade demands it, five minutes head way. Five power plants of 1,000 horse power each, located at Trenton, Rocky Hill, Bound Brook, Westfield and Orange will supply the power.

The road will connect with the principal steam roads of the State. It will intersect both the Pennsylvania and Reading at Trenton, the Pennsylvania at New Brunswick, the Lehigh Valley,