most economic means for the transmission of the energy borrowed from the waterfalls.

In the meantime, a quite new departure, namely, the hydraulic transmission of power, was made at Geneva.* Horizontal water-wheels of a perfected construction, i.e., turbines, driven by the Rhône at its issue from Lake

Leman, were established to pump water to a high-level reservoir, whence it was distributed by means of pipes for consumption in the houses; but being supplied at high pressure, water began to be made use of also in numbers of small workshops, printingoffices, and the like. Altogether, the system answered so well and was so popular with the small industries that when new water-works were installed by the municipality on a larger scale in 1882-86, for utilizing 5400 horsepower, the hydraulic system was maintained. The result was that cheap motive power, readily available in each house, saved the Geneva watch and jewelry industry from an otherwise. unavoidable death; electric light became cheap, and could be obtained in every private establishment by means of private dynamos. Altogether, the new venture was so successful that the example of Geneva was widely imitated in Southern France and Switzerland, and up till now there are engineers who prefer the hydraulic transmission of power to all others.

In the hitherto-mentioned cases of transmission of power mechanical energy was transmitted as such, without transformation. It was taken by means of water-wheels or turbines from a river; it was set to accomplish none but mechanical work-pumping, or compression; and it reached the receiving end of the system without having ceased to be mechanical energy all the time. However, the teachings of Mayer and Séguin, and their followers,

*The system of transmission of power by means of wire ropes was experimented upon on a large scale in Switzerland. No less than 1500 horse-power obtained from the Rhine at Schaffhausen were distributed in this way, in 1876, to a number of factories, up to a distance of two miles. The same system was adopted at Bellegarde and in Zurich. Here also it was found advantageous to run transmission ropes at a very high speed.

the

Joule, Hirn, Faraday, Grove, Helmholtz, and William Thomson, had not been lost. Our generation grew accustomed to the idea that mechanical energy on the one side, and heat, light, and electricity on the other side, are but two different modes of motion, which can easily be transformed the one into the other, and vice versa. Consequently, if we intend to transport mechanical energy, we may send it as mechanical force through a system of pipes, or even in bottles in the shape of a compressed gas; but we may also transform it first into a molecular movement-say, electricity-send electricity along wires, and re-transform it at the receiving end into mechanical energy, without incurring other losses than those which are due to friction and leakage of all sorts.

A great discovery which was made in the early seventies gave a more concrete shape to this theoretical conception. The means of obtaining an electric current are many; but the easiest way, which became quite familiar for the purposes of electric lighting, was the dynamo machine-a wonderful machine, which from the mere toy it was in our youth has now become one of the most powerful engines of modern industry. Its fundamental principle is very simple. If a coil of insulated wire, which is wound round a cylindrical core of soft iron, or several such coils, are made to rotate between the poles of a horseshoe magnet, electric currents are generated in the coils, and the soft-iron cores become magnets themselves. A certain mechanical force is therefore required to keep the coils rotating; otherwise they would stick to the poles of the magnet; and this mechanical force is transformed into electricity, the amount of which depends upon the size of the machine and the rapidity of rotation of the coils. Thousands and thousands of such machines, driven by steam or water power, are now in use in order to obtain electricity for lighting and all other purposes.

But what would happen with such a machine if, instead of driving it by steam, a strong electric current were launched through it? Would not the machine accomplish the reverse trans

formation, and give up mechanical work at its other end? Would it not

*

now become a motor? This is what it does in reality, and the discovery of this property of the dynamo machine was considered by the great creator of the theory of electricity, Clerk Maxwell, as the greatest discovery of the age. It has put in our hands a new means for transmitting energy at a distance. The force, let us say, of a waterfall drives a dynamo, which originates an electric current; this current is transmitted by wires to another dynamo of a slightly modified type; and this latter, after having received the electric current, restitutes mechanical power.

A sudden impulse was thus given to the electrical transmission of power, and installations for that purpose began to be made in Europe and America. And yet an almost insuperable obstacle seemed to stand in the way as soon as power had to be transmitted a considerable distance. It was found that the thickness of the transmission wire had to be increased in proportion with the distance; so that for sending 200 horsepower a distance of 100 miles a wire 1 inch thick-which means nearly 10,000,000 lb. of copper-would have been required.

True it was known that the thickness of the wire could be reduced by increasing the tension, or pressure, of the electric current. Just as in the transmission of power by means of water or compressed air it was found that the diameter of the pipes could be notably reduced by sending the water, or the air, under high pressure, so it was with electrical wires. A much thinner but well-insulated wire would do with very high-tension currents. Consequently, since 1881 it has been proposed (by Marcel Deprez and Carpentier) to raise the electric pressure

before sending electricity along the wire, and to lower down the pressure at the receiving end before distributing electricity in a workshop or in a city. This idea was experimented upon in power transmissions at Munich, at Paris, at Grenoble ; but it was also found that with a direct current (flowing in one direction), such as was obtained then from the dynamo, the limit of possible pressure was soon reached. When an attempt was made to transmit 200 horsepower through 35 miles of a wire inch thick under a high tension (of 6000 volts), the result was a failure.

the

It required the theoretical work of the Turin professor, Ferraris (in 188588) and the inventive and imaginative work of Tesla upon alternate currents to render the electrical transmission of power at a greater distance a possibility, and soon a reality. Such currents, the direction of which is alternately. changed with great rapidity, can really be sent under very high pressures without destroying the wires and motors; but as the driving force is made in such case to fluctuate, two or three alternate currents must be sent to the motor, each of them differing from the others by its phase-that is, attaining its maximal force when the other current is already in decline. The idea of "two-phase" or "polyphase" motors was thus born, and was soon put into practice by DoliwoDobrowolski at the Frankfurt Exhibition of 1891. Most of us will probably remember the sensation which was produced at that time, when it became known that 110 horsepower, taken from a waterfall at Lauffen, had been transmitted by means of electricity a distance of 107 miles to Frankfurt ; and that the loss of power during the transmission was comparatively small, as it was estimated at from 10 to 35 per cent, while it was known that the loss could not be reduced to that extent under any other system of transmission but electricity. The tension. of the current which was used in this case was very great (18,000 volts), but three bare copper wires, each less than one-sixth of an inch thick, supported by poles, like common telegraph wires, and only attached to improved porce

lain insulators, perfectly answered the purpose.

The possibility and the advantages of an electric distribution of power were thus fully demonstrated, and the number of establishments based on this principle began now rapidly to multiply. In a list compiled in 1896, and already incomplete, we have eightyeight transmission plants, by means of which motive power, from 100 to 20,000 horsepower in each establishment (the latter at Montreal, in Canada), is taken from waterfalls or from a central station, transformed into electricity, transmitted as such, and delivered as motive power again at a distance of from 4 to 106 miles.

All these enterprises, including the new one at Geneva, dwindle, however, to very little in comparison with the immense work that has been accomplished for utilizing a small portion of the power of the Niagara. It is known that at the Horseshoe Falls alone no less than 275,000 cubic feet of water drop every second from a height of 165 feet, and that the mechanical power of this tremendous mass of water is equal to the latent power of all the coal that is mined in the world. A very small portion of this colossal store of energy, namely, 120,000 horsepower, is now being diverted for industrial purposes. This great enterprise has already quite a history, the best part of which is the way in which the Niagara Company appealed to the genius and the experience of physicists and engineers of all nations in order to overcome the many difficulties which stood in the way.*

*This history is admirably told, and the works are admirably described, in a profusely illustrated special number of Cassier's Magazine, reprinted in a book form, The Harnessing of Niagara," New York, 1897. It contains ten articles, in which the history of the enterprise and its present conditions are treated in full. A great number of excellent portraits and photographs of the falls adds a great deal to its interest. And yet one must see this wonderful" power-house" and its machines silently producing a transformation of energy, to understand the amount of human intelligence and inventiveness that have been put into this colossal enterprise. Being one of those who have had the good fortune of visiting this great workshop of mechanical power, in company with the members of the British Association, I feel

The leading idea of the Niagara power works is very plain. An open canal, 250 feet wide, takes from the Niagara River, 14 miles above the Falls, a sufficient quantity of water, and brings it to the power-house. There a big pit, 178 feet in depth, was dug out, and immense steel pipes, or penstocks, 74 feet in diameter, were placed vertically in the pit. The water from the canal, on entering each one of these gigantic pipes, drops down it fully 140 feet, and at the lower end of the pipe it drives a horizontal water-wheel, or turbine, capable of developing a force of 5125 horsepower. After having accomplished that work the water flows through a slightly inclined tunnel and rejoins the Niagara River, half a mile below the Falls, without spoiling their beauty in the least.

Motive power is thus obtained 140 feet below the floor of the power-house. Now a vertical shaft, 140 feet long, which is itself a triumph of engineering art, is planted in a vertical position on the turbine, and rotates at a very great speed when the turbine is driven at its full force. On this shaft an immense powerful dynamo is planted, like a mushroom, and is set into a rapid motion by the rotation of the shaft. When it is driven full speed an electric current equivalent to 5000 horsepower is developed. There is room for ten penstocks in the wheel-pit and for ten dynamos of the same force in the power-house, but only three were installed last summer; the others will be made and placed in position in proportion as the demand for Niagara power gradually develops.

66

Each dynamo thus supplies an electric curient equivalent to 5000 horsepower. This current is transmitted to switch-board," where, by simply turning certain handles, it can be sent in various directions. It is, however, a low-tension current, and for transmission along wires, especially to distant places, such as Buffalo (twentysix miles), it must be transformed first into a very high-tension current. This

bound to express my warm thanks to the American engineers for all the kindness with which they explained to us that simple and yet so complicated arrangement.

is accomplished in a special transformer-house, where the current enters the "step-up" transformers, and is brought to a high-tension (20,000 volts) for long-distance transmission. Then it is sent along wires, either underground when the industrial establishment is close by, or by means of overhead wires placed on strong poles and supported by especially effective porcelain insulators when it has to travel all the distance to Buffalo. reaching Buffalo the high-tension current is again reduced to a low-tension, and in this shape it is distributed to the street-car companies and factories.

On

All this seems very plain, and all the plan seems now very rational; but one must read the history of this enterprise to understand how many preliminary schemes had to be considered, and how much thought and skill had to be bestowed upon every part of this machinery. Everything, beginning with the colossal water-pipes or penstocks, and the ways of forging them and placing them in position; the turbines and the shafts, and the fine arrangements for supporting their immense. weights by means of water pressure; and finally the dynamos, the transformers, and the motors-everything had to be worked out almost entirely anew, owing to the novelty and the scale of the enterprise. Only the combined. efforts of engineers of all nations could overcome the thousand the thousand difficulties

which barred the way.*

Time alone will tell whether the enterprise is a commercial success, but from the scientific and engineering point of view it is undoubtedly a decided success. Already now 5000 horsepower are supplied to Buffalo,

To show the international character of the enterprise, it will suffice to say that the International Niagara Commission, which examined the plans for this colossal plant and awarded prizes for the best of them, consisted of Lord Kelvin, Dr. Coleman Sellers of Philadelphia, Colonel Turettini of Geneva, Professor Mascart of the Paris Academy, and Professor Cawthorne Unwin of London. The designers of the turbines were MM. Jaesch and Piccard of Geneva, and the deviser of the dynamos was Professor George Forbes of London; while America, on her side, sup. plied quite a phalanx of brilliant engineers, who devised the general plan and the details of that great venture.

while 13.425 horsepower are delivered. to aluminium, carborundum, calcium carbide (for obtaining acetylene gas), chlorate of potash, soda ash, and other electro-chemical works, as well as for local railways and local lighting. Quite a number of new metallurgical and chemical industries, requiring powerful electric currents for obtaining metals or chemicals, are growing near the Niagara power-house; and there can be no doubt that, in proportion as electric motors are better and better constructed for driving all sorts of machinery, the power derived from the Niagara Falls will be still more widely used for driving machinery in the industrial city of Buffalo, and very probably in many other cities as well.

It is also evident that if a notable success be made in the modes of construction and the efficiency of secondary batteries, or accumulators of electricity, the Niagara power-house will at once become the chief supplier of that stored energy. To have energy stored in a box is evidently the desideratum of the moment, because then the accumulator would really supersede coal in many respects, and become as easily transportable and as easily subdivided as coal is, while for all sorts of autocars light and powerful accumulators would be simply invaluable.

The success achieved at the Niagara Falls evidently gave a powerful impulse to similar establishments everywhere. In Switzerland alone similar works are now in course of construction at Basel, in the Val de Travers, at Soleure, and near Langenthal for bringing a force of nearly 20,000 horsepower into the service of industry; while 6300 horsepower obtained from the two Lutschines (the rivers which water the valleys of Lauterbrunnen and Grindelwald) will soon be utilized for a railway. leading to the top of the Jungfrau. As to Geneva, the new big water-works which are being built on the Rhône will have their power transmitted and distributed now by means of electricity.

Next to Switzerland, one may study the most striking effects of electrical transmission of power from waterfalls in the French department of the Jura. Numbers of small industries which

seemed to be doomed to decay have. been suddenly recalled to life by cheap motive power supplied to the houses in small villages, while a number of quite new industries, such as the polishing of diamonds, stone-cutting, the making of pipes and combs, and so on, were entirely born anew when the power of small waterfalls began to be distributed in the villages by means of electrical transformers. In the United States and Canada scores of establishments, big and small, for the transmission of power borrowed from waterfalls are now built. Many of the electrical tramways of the American towns borrow their motive power from the force of running water; while in Canada

every year brings some new waterfall into the service of industry. Such is the case with the Lachine Rapids, which now supply Montreal with electric light and power; as also the Chaudière Falls and the Deschênes Rapids, which supply power to Ottawa. Nay, even the cataracts of the Nile and the Victoria Falls are studied with the intent of utilizing their energy in Egypt and Matabeleland. The dreams of the founders of the mechanical theory of heat and of the indestructibility of energy are thus realized at a speed and on a scale which these philosopherpoets themselves hardly would have been able to foretell.-Nineteenth Cen tury.

SOME twelve or fifteen years ago a considerable section of Society-that Society which is now occupied in discussing Dunlop tires and patent saddles -was suddenly electrified by accounts of the doings of a famous foreign "quack."

Now there are quacks and quacks; but above and beyond the mass of dishonest and incompetent pretenders who are usually denoted by that nameabove even the respectable class of orthodox and properly trained physicians, there are usually two or three practitioners to be heard of with whom the name, originally given in contempt, remains as an ironical title of distinction.

Such, for example, was Kotzau, the Polish dropsy specialist; and such was Von Eberstein, the aurist, ennobled, oddly enough, by the most unmusical of German monarchs for enabling His Majesty to hear the operas of Wagner.

Such, in fine, was M. Anatole Lavergne, the Swiss-French pastor, village doctor," magnetist," and seer, the fame of whose cures became first known in England at one of our leading uni versities. Stories about him were related, only at second or third hand, with circumstantial care and sometimes with bated breath in half the common rooms; while his methods effectually set the most learned by the ears.

The

most wonderful thing about him, by all accounts, was the power of touch. This, as has been since explained in a scientific periodical, was first revealed to him, when quite a young man, in a singular and striking manner by the effect of the pressure of his fingers upon the growth of vegetation. The tree, the bough that he handled, bore fruit as if by magic, where others remained almost barren. The mere contact of his sensitive hands seemed to give him a mystic knowledge like that of the fairies who could hear the sap rise and the grass grow.

A little later the simple God-fearing pastor had been awestruck by the discovery that the touch of a human hand or body roused in his brain a host of impressions he had first put aside as visionary fancies, but which he gradually learned to be physical and scientific truths.

He had clasped the hand of many a sick or suffering peasant, and before the man opened his mouth had described the accident or the malady, even when its nature had puzzled a trained physician. The very past lives of the sufferers-so far at least as spiritual or physical suffering concerned

seemed to lie open to his gaze. Nay, he had found the power, unaided and unimpeded by any effort or feeling of