With the Bell receiver and the Blake transmitter a good practical telephone system may be constructed, but the improvements which have been made in the short life of the telephone are beyond adequate description, or even mention. They relate to the call bell, the battery, the switchboard, meters for registering calls, conductors, conduits, connections, lightning arresters, switches, anti-induction devices, repeaters, and systems. Among those most prominently identified with its development are Bell, Edison, Berliner, Hughes, Gray, Dolbear and Phelps. The activity in this field is best ill.u.s.trated by the fact that the art of telephony, begun practically in 1876, has at the end of the Nineteenth Century grown into some 3,000 United States patents on the subject.

[Ill.u.s.tration: FIG. 63.--TELEPHONE EXCHANGE.]

That which has given the telephone its greatest commercial value is the "exchange" system, by which at a central office any member of a telephonic community may be instantly put into communication with any other member of that community. For this purpose, see Fig. 63, a continuous switchboard is arranged along the side of a large room and occupies most of that side of the wall. It comprises a great array of annunciator drops, spring jacks with plug seats, and connecting cords with metal plugs at their opposite ends. Each subscriber is connected to his own spring jack and annunciator drop, and his call to central office (from his magneto-bell) throws down the annunciator drop which bears the number of his telephone, and announces to the attendant his desire to communicate with another. To insure the attention of the attendant, a tiny electric lamp is by the same action lighted directly in front of her, which acts as a pilot signal to call her attention to the drop. The attendant now puts a plug in that spring jack, which automatically restores the drop, and she then asks the number which the subscriber wants, and, upon ascertaining this, puts the plug at the other end of the connecting cord into the spring jack of the subscriber wanted, and by this action disconnects her own telephone. As every telephone subscriber has in the central office an apparatus exclusively his own, it will be seen that a telephone community of several thousands of subscribers involves an imposing array of multiple connections, and a great expense in construction. Girls are chosen as exchange attendants because their voices are clearer. Every telephone jack, however, does not have its Jill, for each girl has charge of a hundred or more jacks, and wears constantly on her head a telephone of special shape, embracing her head like a child's hoop comb, but terminating with an ear-piece at one end that covers one ear. She is too busy to waste time in adjusting an ordinary telephone to her ear, and so wears one of special design all the time.

In the twentieth annual report of the American Bell Telephone Company, for the year 1899, the number of telephones in use January 1, 1900, by that company alone, in the United States, was 1,580,101; the miles of wire were 1,016,777, and the daily connections for persons using the telephone were 5,173,803. The gross earnings of the company were $5,760,106.45, and it paid in dividends $3,882,945. The total number of exchange stations of the Bell Company in the princ.i.p.al countries of the world are: United States, 632,946; Germany, 212,121; Great Britain, 112,840; Sweden, 63,685; France, 44,865; Switzerland, 35,536; Russia, 26,865; Austria, 26,664; Norway, 25,376. The United States has nearly 85,000 more than all the others put together.

Since the expiration of the Bell patents many smaller companies have sprung up, and the number of telephones in use has more than doubled in the last five years. Long distance telephony is now carried on up to nearly 2,000 miles, and one may to-day lie in bed in New York and listen to a concert in Chicago, and the vocal exchange of business and social intercourse between cities has become so large a feature of modern life as to justify the organization of a great company for this service alone.

In the Old Testament, Book of Job, x.x.xviii. chapter, 35th verse, it is written: "Canst thou send lightnings that they may go and say unto thee--'Here we are?'" For thousands of years this challenge to Job has been looked upon as a feat whose execution was only within the power of the Almighty; but to-day the inventor--that patient modern Job--has accomplished this seemingly impossible task, for at the end of this Nineteenth Century of the Christian Era, the telephone makes the lightning man's vocal messenger, tireless, faithful, and true, knowing no prevarication, and swifter than the winged messenger of the G.o.ds.

CHAPTER IX.

ELECTRICITY--MISCELLANEOUS.

STORAGE BATTERY--BATTERIES OF PLANTe, FAURE AND BRUSH--ELECTRIC WELDING--DIRECT GENERATION OF ELECTRICITY BY COMBUSTION--ELECTRIC BOATS--ELECTRO-PLATING--EDISON'S ELECTRIC PEN--ELECTRICITY IN MEDICINE--ELECTRIC CAUTERY--ELECTRICAL MUSICAL INSTRUMENTS--ELECTRIC BLASTING.

A prominent factor in the electrical art is the _Storage Battery_, Secondary Battery, or Acc.u.mulator, as it is variously called. A storage battery acts upon the same general principle as the ordinary galvanic or voltaic battery in giving forth electrical current as the correlated equivalent of the chemical force, but differs from it in this respect, that when the elements of a primary battery are used up, the battery is exhausted beyond repair. With the storage battery, it may be regenerated at will by simply subjecting it to an electric current from a dynamo.

The dynamo stores up in this battery its electric force by converting it into chemical force, which is imprisoned in chemical compounds that are formed while the power of the dynamo is being applied. These chemical compounds are, however, in a condition of unstable chemical equilibrium, which is undisturbed so long as the poles of the storage battery are not connected, but when connected through a circuit, the instability of the chemical compounds a.s.serts itself, and in pa.s.sing back to a condition of normal equilibrium the disruption gives off the correlative equivalent of electric current stored up in it by the dynamo.

Probably the earliest suggestion of a storage battery is by Ritter in 1812, in his "secondary pile." This device consisted of alternate discs of copper and moistened card, and was capable of receiving a charge from a voltaic pile and of then producing the physical, chemical, and physiological effects obtained from the ordinary pile. The first storage battery of importance, however, was made by Gaston Plante in 1860, which consisted of leaden plates immersed in a 10 per cent. solution of sulphuric acid in water. In Fig. 64 is shown a modification of the Plante type of storage battery, composed of a series of plates shown on the left. Each of these plates is built up, as shown in detail in Fig.

65, of lead strips corrugated and arranged in layers alternately with flat strips, within perforated leaden cases. The corrugation of the leaden laminae gives greater superficial area, and the alternation of flat and corrugated strips keeps them properly s.p.a.ced, so the sulphuric acid solution may penetrate and act upon the same. Each plate section has a rod to connect it with its proper terminal. When the charging current is applied, the positive lead plate becomes covered with lead peroxide (PbO2) and finely divided metallic lead is deposited on the negative plate. When the battery is being discharged the peroxide of lead gives up one of its atoms of oxygen to the spongy metallic lead deposited on the other plate, and both plates remain coated with lead monoxide (PbO).

[Ill.u.s.tration: FIG. 64.--PLANTe STORAGE BATTERY.]

[Ill.u.s.tration: FIG. 65.--ENLARGED DETAIL OF PLANTe PLATE.]

The most important development of the storage battery was made by Camille A. Faure, in 1880 (U. S. Pat. No. 252,002, Jan 3, 1882). In the early part of 1881 there was sent from Paris to Glasgow a so-called "box of electric energy" for inspection and test by Sir William Thomson, the eminent electrician. It was one of the first storage batteries of M.

Faure. The ill.u.s.tration, Fig. 66, shows a battery of this type in which the lead plates covered with red lead (Pb3O4) replace the plain lead plates in the Plante cell. The action of the battery is that when a current of electricity is pa.s.sed into the same, the red lead on one plate (the negative) is reduced to metallic lead, and that on the other is oxidized to a state of peroxide (PbO2). These actions are reversed when the charged cell is discharging itself. The elements of this battery consist of alternate layers of sheet lead, and a paste of red oxide of lead. These are immersed in a 10 per cent. solution of sulphuric acid in water. Many minor improvements have been made in the storage battery, covered by 716 United States patents, most of which relate to cellular construction for holding the ma.s.s of red lead in place. The most notable are those of Brush, to whom many patents were granted in 1882 and 1883.

[Ill.u.s.tration: FIG. 66.--STORAGE BATTERY--FAURE TYPE.]

The storage battery finds many important applications. For furnishing current for the propulsion of electric street cars it has proved a disappointment, on account of the vibrations to which it is subjected, and the great weight of the lead, which in batteries of suitable capacity runs up into many thousands of pounds. The storage battery finds a useful place, however, for equalizing the load in lighting and power stations, and is there brought into action to supplement the engine and dynamo during those hours of the day when the tax or load is greatest. It is also used to keep up electrical pressure at the ends of long transmission lines; for telegraphing purposes; for isolated electric lighting; for boat propulsion; the propulsion of automobile carriages; and in all cases where a portable source of electric current would find application. The great growth of automobile carriages in the past year has greatly stimulated the output of storage batteries. One large company (The Electric Storage Battery Company), manufactured and sold storage batteries for the year ending June 1, 1899, to the amount of $2,387,049.91, and there are many other manufacturers.

[Ill.u.s.tration: FIG. 67.--ELECTRIC WELDING.]

_Electric Welding_ was invented by Prof. Elihu Thomson, of Lynn, Ma.s.s., and patented by him August 10, 1886, No. 347,140-42, and July 18, 1893, No. 501,546. It is useful for the making of chains, tools, carriage axles, joining shafting, wires, and pipes, mending bands, tires, hoops, and lengthening and shortening bolts, bars, etc. For electric welding a current of great volume or quant.i.ty, and very low electro-motive force, is required. Thus a current of from one to two volts, and one to several thousand amperes, is best suited. Referring to Fig. 67, the current from the dynamo is conducted to one binding post of the commutator 3, which is arranged to send the current through one-sixth, one-third or one-half of the primary wire P of a transformer or induction coil. The other binding post of the commutator 3 extends to one terminal of an isolated primary coil 4, and the other terminal of this coil connects with the dynamo. The coil 4 is provided with a switch to regulate the amount of current. The rods to be welded are placed in clamps C C', C being connected with one terminal of the secondary conductor S, and the movable clamp C' with the other. When the current is turned on C' is moved so as to project one of the surfaces to be welded against the other, and as they come in contact they heat and fuse together, as shown at W. Larger apparatus has been devised to weld railroad joints on the roadbed, and for other applications.

[Ill.u.s.tration: FIG. 68.--GENERATION OF ELECTRICITY BY COMBUSTION.]

_The generation of electricity_ for commercial purposes is almost entirely dependent upon the dynamo, as this is cheaper than the voltaic battery. The dynamo, however, must be energized by a steam engine. The direct production of electric energy by the combustion of coal would be the ideal method. A process invented by Edison (Pat. No. 490,953, Jan.

31, 1893), is interesting as an effort in this direction, and is presented in Fig. 68. A carbon cylinder D is suspended in an air-tight vessel B, and is surrounded by oxide of iron F, the whole being placed above a furnace. The temperature being raised to a point where the carbon will be attacked by the oxygen, carbonic oxide and carbonic acid will be formed, which are exhausted by the suction fan E. A constant current of electricity is given off from the two electrodes through the wires, the metallic oxide being reduced and the carbon consumed.

[Ill.u.s.tration: FIG. 69.--RUDDER AND MOTOR OF TROUVe'S ELECTRIC BOAT, 1881.]

_Electrical Navigation_ began with Jacobi, who made the first attempt on the Neva in 1839. He used voltaic apparatus consisting of two Grove batteries, each containing sixty-four pairs of cells, but little progress was made in this field until the secondary battery was perfected. In 1881 Mr. G. Trouve made an application of the storage battery and electric motor to a small boat on the Seine. The electric motor, which was located on top of the rudder, as seen in Fig. 69, was furnished with a Siemens armature connected by an endless belt with a screw propeller having three paddles arranged in the middle of an iron rudder. In the middle of the boat were two storage batteries connected with the motor by two cords that both served to cover the conducting wires and work the rudder. Electric launches have in later years rapidly gained in popularity. Visitors to the Chicago fair will remember the fleet of electric launches, which afforded both pleasure and transportation on the water, at that great exposition, and to-day every safe harbor has its quota of these silently gliding and fascinating pleasure crafts. Fig. 70 is a longitudinal section and a general view of one of these launches.

[Ill.u.s.tration: FIG. 70.--MODERN ELECTRIC LAUNCH.]

_Electro-plating_ is one of the great industrial applications of electricity which had its origin in, and has grown into extensive use in, the Nineteenth Century. It originated with Volta, Cruikshank, and Wollaston in the very first year of the century. In 1805 Brugnatelli, a pupil of Volta, gilded two large silver medals by bringing them into communication by means of a steel wire with the negative pole of a voltaic pile and keeping them one after the other immersed in a solution of gold. In 1834 Henry Bessemer electro-plated lead castings with copper in the production of antique relief heads. In 1838 Prof. Jacobi announced his galvano-plastic process for the production of electrotype plates for printing. In the same year he superintended the gilding, by electro-plate, of the iron dome of the Cathedral of St. Isaac at St.

Petersburgh, using 274 pounds of ducat gold. In 1839 Spencer described an electrotype process and carried the date of his operations back to September, 1837. In 1839 Jordan also describes an electro-plating process. In 1840 Murray used plumbago to make non-conducting surfaces conductive for electro-plating. In 1840 De Le Rive made known his process of electro-gilding, employed by him in 1828, and in the same year (1840) De Ruolz took out a French patent for electro-gilding, and in the following year formed electro deposits of bra.s.s from cyanides of zinc and copper. In 1841 Smee employed his battery for electro-plating with various metals. In 1844 there were published the electro-plating experiments of Dancer, made in 1838. In 1847 Prof. Silliman imitated mother-of-pearl by electro-plating process.

[Ill.u.s.tration: FIG. 71.--ELECTRO-PLATING ESTABLISHMENT.]

In the last half of the century the production of electrotype plates for printing in books, and for the production of rollers for printing fabrics, and the extensive art of electro-plating with gold, silver, nickel and copper, has grown to enormous proportions, but the fundamental principles have not materially changed. The dynamo, however, has generally supplanted the voltaic battery in this art. The deposition of silver and gold on baser metals not only increases the ornamental effect, but prevents oxidation. Silver plated goods for the table and articles of vertu are to be found everywhere. Nickel is employed for cheaper ornamental effect, and copper finds a large application for electrotypes for printing and for coating iron castings as a protection against rust. In Fig. 71, which shows the interior of an electro-plating establishment, the dynamo is shown on the right connected by wires with two horizontal rods running along the wall and across the various tanks containing the plating solution. On the tanks are rods supporting the articles to be plated, which are suspended in the solution. Similar rods support the opposite electrodes of the tank. Wires connect these rods to the rods on the side of the wall, and to the opposite poles of the dynamo.

[Ill.u.s.tration: FIG. 72.--EDISON'S ELECTRIC PEN.]

_The electric pen of Edison_, brought out in 1876 (U. S. Pat. No.

196,747, Nov. 6, 1877), is one of the simple applications of electricity, which for a number of years was in quite general use for making manifold copies of ma.n.u.script. In the ill.u.s.tration, Fig. 72, this is shown. It comprises a stylus _b_ reciprocated in a tube _a_ by the vibratory action of an armature _k_ over the poles of an electro-magnet, supplied with a suitable current and vibrating contacts _l h_. The stylus was rapidly reciprocated, and as the operator traced the letters on the paper, the stylus produced a continuous trail of punctures which permitted the paper to be used as a stencil to make any number of copies. It has, however, been rotated out of existence by manifolding carbon paper, and the almost universal use of the typewriter.

[Ill.u.s.tration: FIG. 73.--ELECTRIC CAUTERY.]

_Electricity in Medicine._--The superst.i.tious mind is p.r.o.ne to resort to mysterious agencies for the cure of diseases, and for many years men of no scientific knowledge whatever have been employing this seductive instrumentality for all the ills that flesh is heir to. That it has valuable therapeutic qualities when rightly applied no intelligent person will doubt, and it is unfortunate that for the most part it has been in the hands of charlatans who sell their wares, and rely upon a faith-cure principle for the result. Still there have been intelligent experimenters in this field, and it is one of much promise for further research.

In the first century of the Christian Era (A. D. 50) Scribonius Largus relates that Athero, a freedman of Tiberius, was cured of the gout by the shocks of the torpedo or electric eel. In 1803 M. Carpue published experiments on the therapeutic action of electricity. The discovery of induction currents by Faraday in 1831 brought a new era in the medical application of electricity, in the use of what is known as the Faradaic current. The first apparatus for medical use, which operated on this principle, was made by M. Pixii in France, and the first physician who employed such currents was Dr. Neef, of Frankfort. The medical battery is a well-known and useful adjunct to the physician's outfit. Electric baths are also common and effective modes of applying the electric current. An early example of such a device is shown in the U. S. patent to Young, No. 32,332, May 14, 1861. The electric cautery and probe are also scientific and useful instruments. The cautery consists of a loop of platinum wire carried by a suitable non-conducting handle, with means for constricting the white hot loop of wire about the tumor or object to be excised. It was invented in 1846 by Crusell, of St. Petersburgh. A form of the electric cautery is shown in Fig. 73, in which _a_ is the platinum wire loop whose branches slide through guide tubes, the ends being attached to a sliding ring B. The current enters through the wire at the binding posts at the end of non-conducting handle A, and heats the platinum loop, _a_, red hot. The loop, _a_, being around the object to be excised, is constricted by drawing down the handle ring B.

Of the various applications of electricity in body wear and appliances there is scarcely any end. There are patents for belts without number, for electric gloves, rings, bracelets, necklaces, trusses, corsets, shoes, hats, combs, brushes, chairs, couches, and blankets. Patents have also been granted for electric smelling bottles, an adhesive plaster, for electric spectacles, scissors, a foot warmer, hair singer, syringes, a drinking cup, a hair cutter, a torch, a catheter, a pessary, gas lighters, exercising devices, a door mat, and even for an electric hair pin and a pair of electric garters.

_Electrical Musical Instruments_ include pianos, banjos, and violins, all of which are to be played automatically by the aid of electrical appliances. In the ill.u.s.tration, Fig. 74, is shown a modern electrical piano. A small electrical motor 1, run by a storage battery or electric light wires, turns a belt 3, and rotates pulley 4 and a long horizontal cylinder 5 running beneath the keyboard. Above this cylinder is the mechanism that acts upon the keys. It consists of a series of brake shoes which, when brought into frictional contact with the cylinder 5, are made to act on small vertical rods which bring down the keys just as the fingers do in playing. The selection of the proper keys is made by a traveling strip of paper perforated with dots and dashes representing the notes, which strip of paper pa.s.ses between two metal contact faces, which are terminals of an electric battery. When the contacts are separated by the non-conducting paper the current does not flow, but when the contacts come together through the perforations the current is completed through an electro-magnet, and this is made to bring the proper brake shoe into position to be lifted by the cylinder 5, which rotates constantly.

[Ill.u.s.tration: FIG. 74.--ELECTRIC PIANO.]

_Electro-blasting._--In 1812 Schilling proposed to blow up mines by the galvanic current. In 1839 Colonel Pasley blew up the wreck of the "Royal George" by electro-blasting. On Jan. 26, 1843, Mr. Cubitt used electro-blasting to destroy Round Down Cliff, and in our own time the extensive excavations in deepening the channel and removing the rocks at h.e.l.l Gate, from the mouth of New York harbor, was a notable operation in electro-blasting, and doubtless owes its success largely to the electric current employed.

Only the briefest mention can be made of the induction coil and the electrical transformer, of electric bells and hotel annunciators, of electric railway signalling, and electric brakes, of electric clocks and instruments of precision, of heating by electricity, of electrical horticulture, and of the beautiful electric fountains. These, however, all belong to the Nineteenth Century, and include interesting developments.

_Electro-chemistry_ and the _electrolytic refining of metals_ represent also, in the applications of electricity, a large and important field, more fully treated under the chapters devoted to chemistry and metal working.

CHAPTER X.

THE STEAM ENGINE.

HERO'S ENGINE, AND OTHER EARLY STEAM ENGINES--WATT'S STEAM ENGINE--THE CUT-OFF--GIFFARD INJECTOR--BOURDON'S STEAM GAUGE--FEED- WATER HEATERS, SMOKE CONSUMERS, ETC.--ROTARY ENGINES--STEAM HAMMER-- STEAM FIRE ENGINE--COMPOUND ENGINES--SCHLICK AND TAYLOR SYSTEMS OF BALANCING MOMENTUM OF MOVING PARTS--STATISTICS.

When the primeval man first turned upon himself the critical light of introspection, and observed his own deficiencies, there were born within him both the desire and the determination to supplement his weakness, and become the ruling factor in the world's destiny. The strength of his arm unaided could not cope with that of the wild beast, he could not travel so fast as the animal, nor soar so high as the bird, nor traverse the waters of the sea like the fish. The magnificent power of the elements first inspired him with awe, then was worshiped as a G.o.d, and he trembled in his weakness. Then he began to invent, and seeing in physical laws an escape from his fears, and a solution for his ambitions, he trained these forces and made them subservient to his will, and established his right to rule. Out of the maze of the centuries a steam engine is born--not all at once, for that would be inconsistent with the law of evolution--but gradually growing first into practicability, then into efficiency, and finally into perfection, it stands to-day a beautiful monument of man's ingenuity, throbbing with life and energy, and moving the world. What has not the steam engine done for the Nineteenth Century? It speeds the locomotive across the continent faster and farther than the birds can fly; no fish can equal the mighty steamship on the sea; it grinds our grain; it weaves our cloth; it prints our books; it forges our steel, and in every department of life it is the ubiquitous, tireless, potent agency of civilization.

Does the ambitious young philosopher predict that electricity will supersede steam? It is not yet a rational prophecy, for the direct production of electricity from the combustion of coal is still an unsolved problem, and behind the electric generator can always be found the steam engine, modestly and quietly giving its full life's work to the dynamo, which it actuates, and caring nothing for the credit, unmindful of the beautiful and striking manifestations of electricity which astonish the world, but humbly doing its duty with a silent faith that the law of correlation of force will always lead the way back to the steam engine, and place it where it belongs, at the head of all useful agencies of man.

The Nineteenth Century did not include in its discoveries the invention of the steam engine. The great gift of James Watt was one of the legacies which it received from the past, but the economical, efficient, graceful, and mathematically perfect engine of to-day is the product of this age.

[Ill.u.s.tration: FIG. 75.--HERO'S ENGINE, 150 B. C.]