The great importance which electricity has attained in many departments
of human activity is so constantly evident that we have difficulty
in realizing how short is the time which has been occupied in its
development. The latter half of the nineteenth century must ever remain
memorable, not only for the great advances in nearly all the useful
arts, but for the peculiarly rapid electric progress, and the profound
effect which it has had upon the lives and business of the people.
In the preceding century we find no evidences of the application
of electricity to any useful purpose. Few of the more important
principles of the science were then known. Franklin’s invention of
the lightning-rod was not intended to utilize electric force, but
to guard life and property from the perils of the thunder-storm.
The numerous instructive experiments in frictional electricity, the
first-known form of electric manifestation except lightning, made clear
certain principles, such as conduction and insulation, and served to
distinguish the two opposite electric conditions known as positive
and negative. Franklin’s kite experiment confirmed the long-suspected
identity of lightning and electric sparks. It was not, however, until
the discovery by Alexander Volta, in 1799, of his pile, or battery,
that electricity could take its place as an agent of practical value.
Volta, when he made this great discovery, was following the work of
Galvani, begun in 1786. But Galvani in his experiments mistook the
effect for the cause, and so missed making the unique demonstration
that two different metals immersed in a solution could set up an
electric current. Volta, a professor in the University of Pavia and
a foreign member of the Royal Society of England, communicated his
discovery to the president of the society in March, 1800, and brought
to the notice of the world the first means for obtaining a steady flow
of electricity. Before this event electric energy had been known to the
experimenter in pretty effects of attraction and repulsion of light
objects, in fitful flashes of insignificant power, or, as it appeared
in nature, in the fearful bursts of energy during a thunder-storm,
uncontrolled and erratic. The analogous and closely related phenomena
of magnetism had already found an important application in the
navigator’s compass.
The simplest facts of electro-magnetism, upon which much of the later
electrical developments depend, remained entirely unknown until near
the close of the first quarter of the nineteenth century. Magnetism
itself, as exemplified in loadstone or in magnetized iron or steel, had
long before been consistently studied by Dr. Gilbert, of Colchester,
England, and in 1600 his great work, _De Magnete_, was published. It
is a first example, and an excellent one, too, of the application
of the inductive method, so fruitful in after-years. The restraints
which a superstitious age had imposed upon nature study were gradually
removed, and at the beginning of the century just past occasional
decided encouragement began to be given to physical research. It was
this condition which put into the hands of Humphry Davy, of the Royal
Institution, in London, at the opening of the century, a voltaic
battery of some 250 pairs of plates. With this a remarkably fruitful
era of electric discovery began. In 1802 Davy first showed the electric
arc or “arch” on a small scale between pieces of carbon. He also
laid the foundation for future electro-chemical work by decomposing
by the battery current potash and soda, and thus isolating the alkali
metals, potassium and sodium, for the first time. This was in 1807,
and the result was not only to greatly advance the youthful science of
chemistry, but to attract the attention of the world to a new power
in the hands of the scientific worker, electric current. A fund was
soon subscribed by “a few zealous cultivators and patrons of science,”
interested in the discovery of Davy, and he had at his service in 1801
no less than 2000 cells of voltaic battery. With the intense currents
obtained from it he again demonstrated the wonderful and brilliant
phenomenon of the electric arc, by first closing the circuit of the
battery through terminals of hardwood charcoal and then separating
them for a short distance. A magnificent arch of flame was maintained
between the separated ends, and the light from the charcoal pieces
was of dazzling splendor. Thus was born into the world the electric
arc light, of which there are now many hundreds of thousands burning
nightly in our own country alone.
Davy probably never imagined that his brilliant experiment would soon
play so important a part in the future lighting of the world. He may
never have regarded it as of any practical value. In fact, many years
elapsed before any further attempt was made to utilize the light of
the electric arc. The reason for this is not difficult to discover.
The batteries in existence were crude and gave only their full power
for a very short time after the circuit was closed. They were subject
to the very serious defect of rapid polarization, whereby the activity
was at once reduced. A long period elapsed before this defect was
removed. Davy in his experiments had also noted the very intense heat
of the electric arc, and found that but few substances escaped fusion
or volatilization when placed in the heated stream between the carbon
electrodes. Here again he was pioneer in very important and quite
recent electric work, employing the electric furnace, which has already
given rise to several new and valuable industries.
The conduction of electricity along wires naturally led to efforts to
employ it in signalling. As early as 1774 attempts were made by Le
Sage, of Geneva, to apply frictional electricity to telegraphy. His
work was followed before the close of the century by other similar
proposals. Volta’s discovery soon gave a renewed impetus to these
efforts. It was easy enough to stop and start a current in a line of
wire connecting two points, but something more than that was requisite.
A good receiver, or means for recognizing the presence or absence of
current in the wire or circuit, did not exist. The art had to wait for
the discovery of the effects of electric current upon magnets and the
production of magnetism by such currents. Curiously, even in 1802 the
fact that a wire conveying a current would deflect a compass needle was
observed by Romagnosi, of Trente, but it was afterwards forgotten, and
not until 1819 was any real advance made.
It was then that Oersted, of Copenhagen, showed that a magnet tends to
set itself at right angles to the wire conveying current and that the
direction of turning depends on the direction of the current. The study
of the magnetic effects of electric currents by Arago, Ampère, and the
production of the electro-magnet by Sturgeon, together with the very
valuable work of Henry and others, made possible the completion of the
electric telegraph. This was done by Morse and Vail in America, and
almost simultaneously by workers abroad, but, before Morse had entered
the field, Professor Joseph Henry had exemplified by experiments
the working of electric signalling by electro-magnets over a short
line. It was Henry, in fact, who first made a practically useful
electro-magnet of soft iron. The history of the electric telegraph
teaches us that to no single individual is the invention due. The Morse
system had been demonstrated in 1837, but not until 1844 was the first
telegraph line built. It connected Baltimore and Washington, and the
funds for defraying its cost were only obtained from Congress after a
severe struggle. This can easily be understood, for electricity had not
up to that time ever been shown to have any practical usefulness. The
success of the Morse telegraph was soon followed by the establishment
of telegraph lines as a means of communication between all the large
cities and populous districts. Scarcely ten years elapsed before the
possibility of a transatlantic telegraph was mooted. The cable laid
in 1858 was a failure. A few words passed, and then the cable broke
down completely. This was found to be due to defects in construction.
A renewed effort to lay a cable was made in 1866, but disappointment
again followed: the cable broke in mid-ocean and the work again ceased.
The great task was successfully accomplished in the following year, and
the pluck and pertinacity of those who were staking their capital, if
not their reputations for business sagacity, were amply rewarded. Even
the lost cable of 1866 was found, spliced to a new cable, and completed
soon after as a second working line. The delicate instruments for the
working of these long cables were due to the genius of Sir William
Thomson, now Lord Kelvin, whose other instruments for electrical
measurement have for years been a great factor in securing precision
both in scientific and practical testing. The number of cables joining
the Eastern and Western hemispheres has been increased from time to
time, and the opening of a new cable is now an ordinary occurrence,
calling for little or no especial note.
The introduction of the electric telegraph was followed by the
invention of various signalling systems, the most important being
the fire-alarm telegraph, as suggested by Channing and worked out
by Farmer. We now, also, have automatic clock systems, in which a
master clock controls or gives movement to the hands of distant clock
dials by electric currents sent out over the connecting or circuit
wires. Automatic electric signals are made when fire breaks out in a
building, and alarms are similarly rung when a burglar breaks in. Not
only do we have telegraphs which print words and characters, as in the
stock “ticker,” but in the form known as the telautograph, invented
by Dr. Elisha Gray, the sender writes his message, which writing is
at the same time being reproduced at the receiving end of the line.
Even pictures for drawings are “wired” by special instruments. The
desirability of making one wire connecting two points do a large amount
of work, and thus avoiding the addition of new lines, has led to two
remarkable developments of telegraphy. In the duplex, quadruplex, and
multiplex systems several messages may at the same time be traversing
a single wire line without interference one with the other. In the
rapid automatic systems the working capacity of the line is increased
by special automatic transmitting machines and rapid recorders, and the
electric impulses in the line itself follow each other with great speed.
Improvement in this field has by no means ceased, and new systems for
rapid transmission are yet being worked out. The object is to enlarge
the carrying capacity of existing lines connecting large centres of
population. The names of Wheatstone, Stearns, Edison, and Delaney are
prominent in connection with this work. For use in telegraphy the
originally crude forms of voltaic battery, such as Davy used, were
replaced by the more perfect types such as the constant battery of
Daniell, the nitric-acid battery of Grove, dating from 1836, and the
carbon battery of Bunsen, first brought out in 1842. Such was the power
of the Grove and Bunsen batteries that attention was again called
to the electric arc and to the possibility of its use for electric
illumination. Accordingly, we find that suggestions were soon made for
electric-arc lamps, to be operated by these more powerful and constant
sources of electric current. The first example of a working type of
an arc lamp was that brought to notice by W. E. Staite, in 1847, and
his description of the lamp and the conditions under which it could be
worked is a remarkably exact and full statement, considering the time
of its appearance. Staite even anticipated the most recent phase of
development in arc lighting, namely, the enclosure of the light in a
partially air-tight globe, to prevent too rapid waste of the carbons
by combustion in the air. In a public address at Newcastle-on-Tyne,
in 1847, he advocated the use of the arc, so enclosed, in mines,
as obviating the danger of fire. But it was a long time before the
electric arc acquired any importance as a practical illuminant. There
was, indeed, no hope of its success so long as the current had to be
obtained from batteries consuming chemicals and zinc. The expense was
too great, and the batteries soon became exhausted. In spite of this
fact, occasional exhibitions of arc lighting were made, notably in
1856, by Lacassagne and Thiers, in the streets of Paris.
For this service they had invented an arc lamp involving what is known
as the differential principle, afterwards applied so extensively to
arc lamps. The length of the arc or the distance between the carbons
of the lamp was controlled with great nicety, and the light thus
rendered very steady. Even as late as 1875 batteries were occasionally
used to work single electric arc lamps for public exhibitions, or for
demonstration purposes in the scientific departments of schools.
The discovery of the means of efficiently generating electricity
from mechanical power constitutes, however, the key-note of all the
wonderful electrical work of the closing years of the nineteenth
century. It made electrical energy available at low cost. Michael
Faraday, a most worthy successor of Davy at the Royal Institution, in
studying the relations between electric currents and magnets, made the
exceedingly important observation that a wire, if moved in the field of
a magnet, would yield a current of electricity. Simple as the discovery
was, its effect has been stupendous. Following his science for its own
sake, he unwittingly opened up possibilities of the greatest practical
moment. The fundamental principle of the future dynamo electric machine
was discovered by him. This was in 1831. Faraday’s investigations
were so complete and his deductions so masterly, that little was
left to be done by others. Electro-magnetism was supplemented by
magneto-electricity. Both the electric motor and the dynamo generator
were now potentially present with us. Faraday contented himself with
pointing the way, leaving the technical engineer to follow. In one of
Faraday’s experiments a copper disk mounted on an axis passing through
its centre was revolved between the poles of a large steel magnet. A
wire touched the periphery of the disk at a selected position with
respect to the magnet, and another was in connection with the axis.
These wires were united through a galvanometer or instrument for
detecting electric current. A current was noted as present in the
circuit so long as the disk was turned. Here, then, was the embryo
dynamo. The century closed with single dynamo machines of over 5000
horse-power capacity, and with single power stations in which the total
electric generation by such machines is 75,000 to 100,000 horse-power.
So perfect is the modern dynamo that out of 1000 horse-power expended
in driving it, 950 or more may be delivered to the electric line as
electric energy. The electric motor, now so common, is a machine like
the dynamo, in which the principle of action is simply reversed;
electric energy delivered from the lines becomes again mechanical
motion or power.
Soon after Faraday’s discoveries in magneto-electricity attempts
were made to construct generators of electricity from power. But the
machines were small, crude, and imperfect, and the results necessarily
meagre.
Pixii, in Paris, one year after Faraday’s discovery was announced, made
a machine which embodied in its construction a simple commutator for
giving the currents a single direction of flow. This is the prototype
of the commutators now found on what are called continuous-current
dynamos. After Pixii followed Saxton, Clarke, Wheatstone and Cooke,
Estohrer, and others, but not until 1854 was any very notable
improvement made or suggested. In that year Soren Hjorth, of
Copenhagen, described in a patent specification the principle of
causing the electric currents generated to traverse coils of wire so
disposed as to reinforce the magnetic field of the machine itself.
A year subsequently the same idea was again more clearly set out by
Hjorth. This is the principle of the modern self-exciting dynamo,
the field magnets of which, very weak at the start, are built up or
strengthened by the currents from the armature or revolving part of the
machine in which power is consumed to produce electricity.
In 1856 Dr. Werner Siemens, of Berlin, well known as a great pioneer in
the electric arts, brought out the Siemens armature, an innovation more
valuable than any other made up to that time. This was subsequently
used in the powerful machines of Wilde and Ladd. It still survives in
magneto call-bell apparatus for such work as telephone signalling,
in exploders for mines and blasting, and in the simpler types of
electroplating dynamos.
The decade between 1860 and 1870 opened a new era in the construction
and working of dynamo machines and motors. It is notable for two
advances of very great value and importance. Dr. Paccinotti, of
Florence, in 1860, described a machine by which true continuous
currents resembling battery currents could be obtained. Up to that
time machines gave either rapidly alternating or fluctuating currents,
not steady currents in one direction. The Paccinotti construction, in
modified forms, is now almost universally employed in dynamo machines,
and even where the form is now quite different the Paccinotti type has
been at least the forerunner, and has undergone modifications to suit
special ends in view. Briefly, Paccinotti made his armature of a ring
of iron with iron projections between which the coils of insulated
wire were wound. Although full descriptions of Paccinotti’s ring
armature and commutator were given out in 1864, his work attracted but
little attention until Gramme, in Paris, about 1870, brought out the
relatively perfect Gramme machine. In the mean time the other great
development of the decade took place.
Although Hjorth had, as stated before, put forward the idea that a
dynamo generator might itself furnish currents for magnetizing its own
magnets, this valuable suggestion was not apparently worked out until
1866, when a machine was constructed for Sir Charles Wheatstone. This
appears to have been the first self-exciting machine in existence.
Wheatstone read a paper before the Royal Society in February, 1867, “On
the Augmentation of the Power of a Magnet by the Reaction thereon of
Currents Induced by the Magnet Itself.” This action later became known
as the reaction principle in dynamo machines.
As often happens, the idea occurred to other workers in science almost
simultaneously, and Dr. Werner Siemens also read a paper in Berlin
about a month earlier than that of Wheatstone, clearly describing
the reaction principle. Furthermore, a patent specification had
been filed in the British Patent Office by S. A. Varley, December
24, 1866, clearly showing the same principle of action, and he was,
therefore, the first to put the matter on record. The time was ripe
for the appearance of machines closely resembling the types now in
such extended use. Gramme, in 1870, adopting a modified form of the
Paccinotti ring and commutator, and employing the reaction principle,
first succeeded in producing a highly efficient, compact, and durable
continuous-current dynamo. The Gramme machine was immediately
recognized as a great technical triumph. It was in a sense the
culmination of many years of development, beginning with the early
attempts immediately following Faraday’s discovery, already referred
to. Gramme constructed his revolving armature of a soft iron wire ring,
upon which ring a series of small coils of insulated wire were wound
in successive radial planes. These coils were all connected with a
continuous wire and from the junctions of the coils one with another
connections were taken to a range of copper bars insulated from each
other, constituting the commutator. In 1872 Von Hefner Alteneck, in
Berlin, modified the ring winding of Gramme and produced the “drum
winding,” which avoided the necessity for threading wire through the
centre of the iron ring as in the Gramme construction. The several
coils of the drum were still connected, as in Gramme’s machine, to the
successive strips of the commutator.
In modern dynamos and motors the armature, usually constructed of
sheet-iron punchings, is a ring with projections as in Paccinotti’s
machine, and the coils of wire are in most cases wound separately and
then placed in the spaces between the projections, constituting in fact
a form of drum winding. In the early 70’s a few Gramme ring and Siemens
drum machines had been applied to the running of arc lights, one
machine for each light. There were also some Gramme machines in use for
electroplating.
At the Centennial Exhibition, held at Philadelphia in 1876, but two
exhibits of electric-lighting apparatus were to be found. Of these
one was the Gramme and the other the Wallace-Farmer exhibit. The
Wallace-Farmer dynamo machine is a type now obsolete. It was not a good
design, but the Wallace exhibit contained other examples reflecting
great credit on this American pioneer in dynamo work. Some of these
machines were very similar in construction to later forms which went
into very extensive use. The large search-lights occasionally used in
night illumination during the exhibitions were operated by the current
from Wallace-Farmer machines. The Gramme exhibit was a remarkable
exhibit for its time. Though not extensive, it was most instructive.
There were found in it a dynamo running an arc lamp; a large machine
for electrolytic work, such as electroplating or electrotyping, and,
most novel and interesting of all, one Gramme machine driven by power
was connected to another by a pair of wires and the second run as a
motor. This in turn drove a centrifugal-pump, and raised water which
flowed in a small fall or cataract. A year or two previously the Gramme
machine had been accidentally found to be as excellent an electric
motor as it was a generating dynamo. The crude motors of Jacobi,
Froment, Davenport, Page, Vergnes, Gaume, and many others, were thus
rendered obsolete at a stroke. The first public demonstration of the
working of one Gramme machine by another was made by Fontaine at the
Vienna Exhibition of 1873.
Here, then, was a foreshadowing of the great electric-power
transmission plants of to-day; the suggestion of the electric station
furnishing power as well as light, and, to a less degree, the promise
of future railways using electric power. Replace the centrifugal pump
of this modest exhibit by a turbine wheel, reverse the flow of water so
as to cause it to drive the electric motor so that the machine becomes
a dynamo, and, in like manner, make of the dynamo a motor, and we
exemplify in a simple way recent great enterprises using water-power
for the generation of current to be transmitted over lines to distant
electric motors or lights.
The Centennial Exhibition also marks the beginning—the very birth,
it may be said—of an electric invention destined to become, before
the close of the century, a most potent factor in human affairs. The
speaking telephone of Alexander Graham Bell was there exhibited for the
first time to the savants, among whom was the distinguished electrician
and scientist Sir William Thomson. For the first time in the history of
the world a structure of copper wire and iron spoke to a listening ear.
Nay, more, it both listened to the voice of the speaker and repeated
the voice at a far-distant point. The instruments were, moreover, the
acme of simplicity. Within a year many a boy had constructed a pair of
telephones at an expenditure for material of only a few pennies. In
its first form the transmitting telephone was the counterpart of the
receiver, and they were reversible in function. The transmitter was in
reality a minute dynamo driven by the aërial voice waves; the receiver,
a vibratory motor worked by the vibratory currents from the transmitter
and reproducing the aërial motions. This arrangement, most beautiful
in theory, was only suited for use on short lines, and was soon
afterwards replaced by various forms of carbon microphone transmitter,
to the production of which many inventors had turned their attention,
notably Edison, Hughes, Blake, and Hunnings. In modern transmitters
the voice wave does not furnish the power to generate the telephone
current, but only controls the flow of an already existing current from
a battery. In this way the effects obtainable may be made sufficiently
powerful for transmission to listeners 1500 miles away.
There is no need to dwell here upon the enormous saving of time secured
by the telephone and the profound effect its introduction has had upon
business and social life. The situation is too palpable. Nevertheless,
few users of this wonderful invention realize how much thought and
skill have been employed in working out the details of exchange
switchboards, of signalling devices, of underground cables and overhead
wires, and of the speaking instruments themselves. Few of those who
talk between Boston and Chicago know that in doing so they have for
the exclusive use of their voices a total of over 1,000,000 pounds of
copper wire in the single line. There probably now exist in the United
States alone between 75,000 and 100,000 miles of hard-drawn copper wire
for long-distance telephone service, and over 150,000 miles of wire in
underground conduits. There are upward of three-quarters of a million
telephones in the United States, and, including both overhead and
underground lines, a total of more than half a million miles of wire.
Approximately one thousand million conversations are annually conveyed.
The possibility of sub-oceanic telephoning is frequently discussed, but
the problem thus far is not solved. It involves grave difficulties, and
we may hope that its solution is to be one of the advances which will
mark the twentieth century’s progress.
The advent of the telephone in 1876 seemed to stimulate invention in
the electric field to a remarkable degree. Its immediate commercial
success probably acted also to inspire confidence in other proposed
electric enterprises. Greater attention than ever before began to
be given to the problem of electric lighting. An electric arc lamp,
probably the only one in regular use, had been installed at Dungeness
Light-house in 1862, after a long set of trials and tests. It was fed
by a Holmes magneto-electric machine of the old type, very large and
cumbrous for the work. Numerous changes and improvements had before
1878 been made in arc lamps by Serrin, Duboscq, and many others.
But the display of electric light during the Paris Exposition of
1878 was the first memorable use of the electric light on a large
scale. The splendid illumination of the Avenue de l’Opéra was a grand
object-lesson. The source of light was the “electric candle” of Paul
Jablochkoff, a Russian engineer. It was a strikingly original and
simple arc lamp. Instead of placing the two carbons point to point,
as had been done in nearly all previous lamps, he placed them side by
side, with a strip of baked kaolin between them. The candle so formed
was supported in a suitable holder, whereby, at the lower end, the
two parallel carbons were connected with the circuit terminals. By a
suitable device the arc was started at the top and burned down. The
electric candle seemed to solve the problem of allowing complicated
mechanism for feeding the carbons to be discarded; but it survived
only a short time. Owing to unforeseen difficulties it was gradually
abandoned, after having served a great purpose in directing the
attention of the world to the possibilities of the electric arc in
lighting.
Inventors in America were not idle. By the close of 1878, Brush, of
Cleveland, had brought out his series system of arc lights, including
special dynamos, lamps, etc., and by the middle of 1879 had in
operation machines each capable of maintaining sixteen arc lamps
on one wire. This was, indeed, a great achievement for that time.
Weston, of Newark, had also in operation circuits of arc lamps, and the
Thomson-Houston system had just started in commercial work with eight
arc lamps in series from a single dynamo. Maxim and Fuller, in New
York, were working arc lamps from their machines, and capital was being
rapidly invested in new enterprises for electric lighting. Some of the
great electric manufacturing concerns of to-day had their beginning
at that time. Central lighting stations began to be established in
cities, and the use of arc lights in street illumination and in stores
grew rapidly. More perfect forms of arc lamps were invented, better
generating dynamos and regulating apparatus brought out. Factories
for arc-light carbon making were built. The first special electrical
exhibition was held in Paris in 1881. In the early 80’s, also, the
business of arc lighting had become firmly established, and soon the
bulk of the work was done under two of the leading systems. These were
afterwards brought together under one control, thus securing in the
apparatus manufactured a combination of the good features of both.
Until about 1892 nearly all the arc lamps in use were worked under the
series system, in which the lights are connected one after another on a
circuit and traversed by the same current. This current has a standard
value, or is a constant current. Sometimes as many as a hundred lamps
were on one wire. As the mains for the supply of incandescent lamps
at constant pressure, or potential, were extended, attention was more
strongly turned to the possibility of working arc lights therefrom.
Within a few years of the close of the century this placing of arc
lamps in branches from the same mains which supply incandescent lamps
became common, and the enclosure of the arc in a partially air-tight
globe, a procedure advocated by Staite, in 1847, was revived by
Howard, Marks, and others for saving carbons and attention to the lamp.
The enclosed arc lamp was also found to be especially adapted to use in
branches of the incandescent lamp circuits, which had in cities become
greatly extended. The increasing employment of alternating currents
in the distribution of electric energy has led also to the use of
alternating current arc lamps, and special current-regulating apparatus
is now being applied on a large scale to extended circuits of these
lamps. It can be seen from these facts that the art is still rapidly
progressing and the field ever widening. A little over twenty years
ago practically no arc lamps were used. At the close of the century,
they were numbered by hundreds of thousands. The annual consumption of
carbons in this country has reached two hundred millions.
Almost simultaneously with the beginning of the commercial work of arc
lighting, Edison, in a successful effort to provide a small electric
lamp for general distribution in place of gas, brought to public notice
his carbon filament incandescent lamp.
A considerable amount of progress had previously been made by various
workers in attempting to reduce the volume of light in each lamp and
increase the number of lights for a given power expended. Forms of
incandescent arc lamps, or semi-incandescent lamps, were tried on a
considerable scale abroad, but none have survived. So, also, many
attempts to produce a lamp giving light by pure incandescence of solid
conductors proved for the most part abortive. Edison himself worked
for nearly two years on a lamp based upon the old idea of incandescent
platinum strips or wires, but without success. The announcement of
this lamp caused a heavy drop in gas shares, long before the problem
was really solved by a masterly stroke in his carbon filament lamp.
Curiously, the nearest approach to the carbon filament lamp had been
made in 1845, by Starr, an American, who described in a British patent
specification a lamp in which electric current passed through a thin
strip of carbon kept it heated while surrounded by a glass bulb in
which a vacuum was maintained. Starr had exhibited his lamps to
Faraday, in England, and was preparing to construct dynamos to furnish
electric current for them in place of batteries, but sudden death put
an end to his labors. The specification describing his lamp is perhaps
the earliest description of an incandescent lamp of any promise, and
the subsequently recorded ideas of inventors up to the work of Edison
seem now to be almost in the nature of retrograde movements. None of
them were successful commercially. Starr, who was only twenty-five
years of age, is reported to have died of overwork and worry in his
efforts to perfect his invention. His ideas were evidently far in
advance of his time.
The Edison lamp differed from those which preceded it in the extremely
small section of the carbon strip rendered hot by the current, and in
the perfection of the vacuum in which it was mounted. The filament
was first made of carbonized paper, and afterwards of bamboo carbon.
The modern incandescent lamp has for years past been provided with a
filament made by a chemical process. The carbon formed is exceedingly
homogeneous and of uniform electric resistance. Edison first exhibited
his lamp in his laboratory at Menlo Park, New Jersey, in December,
1879; but before it could be properly utilized an enormous amount of
work had to be done. His task was not merely the improvement of an art
already existing; it was the creation of a new art. Special dynamo
machines had to be invented and constructed for working the lamps;
switches were needed for connecting and disconnecting lamps and groups
of lamps; meters for measuring the consumption of electric energy were
wanted; safety fuses and cut-offs had to be provided; electroliers or
fixtures to support the lamp were required; and, lastly, a complete
system of underground mains with appurtenances was a requisite for city
plants.
Even the steam-engines for driving the dynamos had to be remodelled
and improved for electric work, and ten years of electric lighting
development did more towards the refinement and perfection of
steam-engines than fifty years preceding. Steadiness of lights meant
the preservation of steady speed in the driving machinery. The Pearl
Street station in New York City was the first installation for the
supply of current for incandescent lighting in a city district. The
constant pressure dynamos were gradually improved and enlarged. The
details of all parts of the system were made more perfect, and in the
hands of Edison and others the incandescent lamps, originally of high
cost, were much cheapened and the quality of the production was greatly
improved. Lamps originally cost one dollar each. The best lamps that
are made can be had at present for about one-fifth that price. Millions
of incandescent lamps are annually manufactured. Great lighting
stations furnish the current for the working of these lamps, some
stations containing machinery aggregating many thousands of horse-power
capacity. Not only do these stations furnish electric energy for the
working of arc lamps and incandescent lamps, but, in addition, for
innumerable motors ranging in size from the small desk fan of one-tenth
horse-power up to those of hundreds of horse-power. The larger sizes
replace steam or hydraulic power for elevators, and many are used in
shops and factories for driving machinery such as printing-presses,
machinery tools, and the like.
In spite of the fact that it was well known that a good dynamo when
reversed could be made a source of power, few electric motors were
in use until a considerable time after the establishment of the first
lighting stations. Even in 1884, at the Philadelphia Electrical
Exhibition, only a few electric motors were shown. Not until 1886 or
thereafter did the “motor load” of an electric station begin to be a
factor in its business success. The motors supplied are an advantageous
adjunct, inasmuch as they provide a day load, increasing the output
of the station at a time when the lighting load is small and when the
machinery in consequence would, without them, have remained idle. The
growth of the application of electric motors in the closing years of
the century has been phenomenal, even leaving out of consideration
their use in electric railways.
Twenty years ago an electric motor was a curiosity; fifty years ago
crude examples run by batteries were only to be occasionally found in
cabinets of scientific apparatus. Machinery Hall, at the Centennial
Exhibition of 1876, typified the mill of the past, never again to be
reproduced, with its huge engine and lines of heavy shafting and belts
conveying power to the different tools or machines in operation. The
modern mill or factory has its engines and dynamos located wherever
convenient, its electric lines and numerous motors connected thereto,
and each of them either driving comparatively short lines of shafting
or attached to drive single pieces of machinery. The wilderness of
belts and pulleys which used to characterize a factory is gradually
being cleared away, and electric distribution of power substituted.
Moreover, the lighting of the modern mill or factory is done from the
same electric plant which distributes power.
The electric motor has already partly revolutionized the distribution
of power for stationary machinery, but as applied to railways in place
of animal power the revolution is complete. The period which has
elapsed since the first introduction of electric railways is barely a
dozen years. It is true that a few tentative experiments in electric
traction were made some time in advance of 1888, notably by Siemens,
in Berlin, in 1879 and 1880, by Stephen D. Field, by T. A. Edison, at
Menlo Park, by J. C. Henry, by Charles A. Van Depoele, and others. If
we look farther back we find efforts such as that of Farmer, in 1847,
to propel railway cars by electric motors driven by currents from
batteries carried on the cars. These efforts were, of course, doomed to
failure, for economical reasons. Electric energy from primary batteries
was too costly, and if it had been cheaper, the types of electric motor
used yielded so small a return of power for the electric energy spent
in driving them that commercial success was out of the question. These
early efforts were, however, instructive, and may now be regarded
as highly suggestive of later work. Traction by the use of storage
batteries carried on an electric car has been tried repeatedly, but
appears not to be able to compete with systems of direct supply from
electric lines. The plan survives, however, in the electric automobile,
many of which have been put into service within a year or two. The
electric automobile is not well fitted for country touring; it is
best adapted to cities, where facilities for charging and caring for
the batteries can be had. Moreover, the electric carriage is of all
automobile carriages the most easily controlled, most ready; it emits
no smell or hot gases and is nearly noiseless.
About 1850, Hall, a well-known instrument maker of Boston, catalogued
a small toy electric locomotive dragging a car upon rails which were
insulated and connected with a stationary battery of two Grove cells.
This arrangement was sold as a piece of scientific apparatus, and
appears to be the first example of an electrically driven vehicle
connected by rolling contacts to an immovable energy source. Other
early experimenters, such as Siemens, Field, and Daft, subsequently
to Hall, used in actual railway work the supply by insulated tracks.
This was supplanted later by overhead insulated wires or by the
insulated third rail. Siemens & Halske, of Berlin, used a special
form of overhead supply in 1881, and during the electrical exhibition
in Paris in that year, a street tramway line was run by them. Later,
Edison experimented with a third-rail-supply line at Menlo Park; and
at Portrush, in Ireland, an actual railway was put in operation by
Siemens & Halske, using the third-rail system. This was about 1883. The
power of the Portrush railway was that of a water-wheel driving the
generating dynamo.
The modern overhead trolley, or under-running trolley, as it is called,
seems to have been first invented by Van Depoele, and used by him
in practical electric railway work about 1886 and thereafter. The
universality of this invention for overhead supply marks the device
as a really important advance in the art of electric traction. Van
Depoele was also a pioneer in the use of an underground conduit, which
he employed successfully in Toronto in 1884. The names of Edward M.
Bentley and Walter H. Knight stand out prominently in connection with
the first use of an underground conduit, tried under their plans in
August, 1884, at Cleveland, on the tracks of the horse-railway company.
We have barely outlined the history of the electric-motor railway up to
the beginning of a period of wonderful development, resulting in the
almost complete replacement by electric traction of horse traction or
tramway lines, all within an interval of scarcely more than ten years.
The year 1888 may be said to mark the beginning of this work, and in
that year the Sprague Company, with Frank J. Sprague at its head,
put into operation the electric line at Richmond, Virginia, using
the under-running trolley. Mr. Sprague had been associated with
Edison in early traction work, and was well known in connection with
electric-motor work in general. The Richmond line was the first large
undertaking. It had about thirteen miles of track, numerous curves,
and grades of from three to ten per cent. The enterprise was one of
great hardihood, and but for ample financial backing and determination
to spare no effort or expenditure conducive to success, must certainly
have failed. The motors were too small for the work, and there had not
been found any proper substitute for the metal commutator brushes on
the motors—a source of endless trouble and of an enormous expense for
repairs. Nevertheless, the Richmond installation, kept in operation as
it was in spite of all difficulties, served as an object-lesson, and
had the effect of convincing Mr. Henry M. Whitney and the directors
of the West End Street Railway, of Boston, of the feasibility of
equipping the entire railway system of Boston electrically. Meanwhile
the merging of the Van Depoele and Bentley-Knight interests into the
Thomson-Houston Electric Light Company brought a new factor into the
field, the Sprague interests being likewise merged with the Edison
General Electric Company.
The West End Company, with two hundred miles of track in and around
Boston, began to equip its lines in 1888 with the Thomson-Houston
plant. The success of this great undertaking left no doubt of the
future of electric traction. The difficulties which had seriously
threatened future success were gradually removed.
The electric railway progress was so great in the United States that
about January 1, 1891, there were more than two hundred and forty lines
in operation. About thirty thousand horses and mules were replaced by
electric power in the single year of 1891. In 1892 the Thomson-Houston
interests and those of the Edison General Electric Company were merged
in the General Electric Company, an event of unusual importance, as
it brought together the two great competitors in electric traction at
that date. Other electric manufacturers, chief among which was the
Westinghouse Company, also entered the field and became prominent
factors in railway extension. In a few years horse traction in the
United States on tramway lines virtually disappeared. Many cable lines
were converted to electric lines, and projects such as the Boston
Subway began to be planned. Not the least of the advantages of electric
traction is the higher speed attainable with safety. The comfort and
cleanliness of the cars, lighted brilliantly at night, and heated in
winter by the same source of energy which is used to propel them, are
important factors.
All these things, together with the great extension of the lines into
suburban and country districts, and the interconnection of the lines
of one district with those of another, cannot fail to have a decidedly
beneficial effect upon the life, habits, and health of the people.
While the United States and Canada have been and still are the theatre
of the enormous advance in electric traction, as in other electric
work, many electric car lines have in recent years been established in
Great Britain and on the continent of Europe. Countries like Japan,
Australia, South Africa, and South America have also in operation many
electric trolley lines, and the work is rapidly extending. Most of
this work, even in Europe, has been carried out either by importation
of equipment from America, or by apparatus manufactured there, but
following American practice closely. The bulk of the work has been done
with the overhead wire and under-running trolley, but there are notable
instances of the use of electric conductors in underground slotted
conduits, chief of which are the great systems of street railway in New
York City.
In Chicago the application of motor-cars in trains upon the elevated
railway followed directly upon the practical demonstration at the
World’s Fair of the capabilities of third-rail electric traction on the
Intramural Elevated Railway, and the system is rapidly extending so as
to include all elevated city roads. A few years will doubtless see the
great change accomplished.
The motor-car, or car propelled by its own motors, has also been
introduced upon standard steam roads to a limited extent as a
supplement to steam traction. The earliest of these installations are
the one at Nantasket, Massachusetts, and that between Hartford and
New Britain, in Connecticut. A number of special high-speed lines,
using similar plans, have gone into operation in recent years. The
problem of constructing electric motors of sufficient robustness for
heavy work and controlling them effectively was not an easy one, and
the difficulties were increased greatly because of the placing of
the motors under the car body, exposed to wet, to dust and dirt of
road. The advantage of the motor-car, or motor-car train, is that the
traction or hold upon the track increases with the increase of the
weight or load carried. It is thus able to be accelerated rapidly
after a stop, and also climb steep grades without slipping its wheels.
Nevertheless, there are circumstances which favor the employment of a
locomotive at the head of a train, as in steam practice. This is the
case in lines where a train of coal or ore cars is drawn by electric
mining locomotives. Many such plants are in operation, and, at the same
time the electric power is used to drive fans for ventilating, pumps
for drainage, electric hoists, etc., besides being used for lighting
the mines. The trains in the tunnels of the Metropolitan Underground
Railway of London have for many years been operated by steam
locomotives with the inevitable escape of steam, foul, suffocating
gases, and more or less soot.
A number of years ago the tunnel of the City and South London Railway
was put into successful operation with electric locomotives drawing the
trains of cars, and the nuisance caused by steam avoided. This work
recalls the early efforts of Field, of Daft, and Bentley and Knight
in providing an electric locomotive for replacing the steam plant of
the elevated roads in New York City. Well-conceived as many of these
plans were, electric traction had not reached a sufficient development,
and the efforts were abandoned after several more or less successful
trials. It is now seen that the motor-car train may advantageously
replace the locomotive-drawn train in such instances as these elevated
railways.
The three largest and most powerful electric locomotives ever put
into service are those which are employed to take trains through the
Baltimore and Ohio Railroad tunnel at Baltimore. They have been in
service about seven or eight years, and are fully equal in power to
the large steam locomotives used on steam roads. Frequently trains of
cars, including the steam locomotive itself, are drawn through the
tunnel by these huge electric engines, the fires on the steam machines
being for the time checked so as to prevent fouling the air of the
tunnel. There was opened, in London, in 1900, a new railway called the
Central Underground, equipped with twenty-six electric locomotives for
drawing its trains. The electric and power equipment, which embodied in
itself the latest results of American practice, was also manufactured
in America to suit the needs of the road. Other similar railways are
in contemplation in London and in other cities of Europe. As on the
elevated roads in New York City, the replacement of underground steam
traction, where it exists, by electric traction is evidently only a
question of a few years.
An electric railway may exemplify a power-transmission system in which
power is delivered to moving vehicles. But the distances so covered are
not generally more than a few miles from the generating station. Where,
however, abundant water-power exists, as at Niagara, or where fuel is
very expensive and power is to be had only at great distances from
the place at which it is to be used, electricity furnishes the most
effective means for transmission and distribution. Between the years
1880 and 1890 the device called alternating current transformer was
developed to a considerable degree of perfection. It is, in reality, a
modified induction coil, consisting of copper wire and iron, whereby a
current sent through one of its coils will induce similar currents in
the other coils of apparatus. It has the great advantage of having no
moving parts. Faraday, in 1831, discovered the fundamental principle
of the modern transformer. Not only, however, will the current in
one coil of the apparatus generate by induction a new current in an
entirely separate coil or circuit, but by suitably proportioning the
windings we may exchange, as it were, a large low-pressure current for
a small but high-pressure current, or _vice versa_. This exchange may
be made with a very small percentage of loss of energy. These valuable
properties of the transformer have rendered it of supreme importance
in recent electrical extension. The first use made of it, in 1885–86,
was to transform a high-pressure current into one of low pressure in
electric lighting, enabling a small wire to be used to convey electric
energy at high pressure, and without much loss, to a long distance
from the station. This energy at high pressure reaches the transformer
placed within or close to the building to be lighted. A low-pressure
safe current is conveyed from the transformer to the wires connected to
the lamps. In this way a current of two thousand volts, an unsafe and
unsuitable pressure for incandescent lighting, is exchanged for one
of about one hundred volts, which is quite safe. In this way, also,
the supply station is enabled to reach a customer too far away to be
supplied directly with current at one hundred volts, without enormous
expense for copper conductors.
The alternating current transformer not only greatly extended the
radius of supply from a single station, but also enabled the station
to be conveniently located where water and coal could be had without
difficulty. It also permitted the distant water-powers to become
sources of electric energy for lighting, power, or for other service.
For example, a water-power located at a distance of fifty to one
hundred miles or more from a city, or from a large manufacturing centre
where cost of fuel is high, may be utilized as follows: A power-station
will be located upon the site of the water-power, and the dynamos
therein will generate electricity at, say, two thousand volts pressure.
By means of step-up transformers this will be exchanged for a current
of thirty thousand volts for transmission over a line of copper or
aluminum wire to the distant consumption area. Here there will be a set
of step-down transformers which will exchange the thirty-thousand-volt
line current for one of so low a pressure as to be safe for local
distribution to lamps, to motors, etc., either stationary or upon a
railway. The same transmission plant may simultaneously supply energy
for lighting, for power, for heat, and for charging storage batteries.
It may, therefore, be employed both day and night.
These long-distance power transmission plants are generally spoken of
as “two-phase,” “three-phase,” or “polyphase” systems. Before 1890
no such plants existed. A large number of such installations are now
working over distances of a few miles up to one hundred miles. They
differ from what are known as single-phase alternating systems in
employing, instead of a single alternating current, two, three, or
more, which are sent over separate lines, and in which the electric
impulses are not simultaneous, but follow each other in regular
succession, overlapping each other’s dead points, so to speak. Early
suggestions of such a plan, about 1880, and thereafter, by Bailey,
Deprez, and others, bore no fruit, and not until Tesla’s announcement
of his polyphase system, in 1888, was much attention given to the
subject. A widespread interest in Tesla’s work was invoked, but several
years elapsed before engineering difficulties were overcome. This work
was done mainly by the technical staffs of the large manufacturing
companies, and it was necessary to be done before any notable power
transmissions on the polyphase system could be established. After 1892
the growth became very rapid.
The falls of Niagara early attracted the attention of engineers to
the possibility of utilizing at least a fraction of the power. It
was seen that several hundred thousand horse-power might be drawn
from it without materially affecting the fall, itself equivalent to
several millions of horse-power. A gigantic power-station has lately
been established at Niagara, taking water from a distance above the
falls and delivering it below the falls through a long tunnel which
forms the tail race. Ten water-wheels, located in an immense wheel-pit
about two hundred feet deep, each wheel of a capacity of five thousand
horse-power, drive large vertical shafts, at the upper end of which
are located the large two-phase dynamos, each of five thousand
horse-power. The electric energy from these machines is in part raised
in pressure by huge transformers for transmission to distant points,
such as the city of Buffalo, and a large portion is delivered to the
numerous manufacturing plants located at moderate distances from the
power-station. Besides the supply of energy for lighting, and for
motors, including railways, other recent uses of electricity to which
we have not yet alluded are splendidly exemplified at Niagara. Davy’s
brilliant discovery of the alkali metals, sodium and potassium, at
the opening of the century, showed the great chemical energy of the
electric current. Its actions were afterwards carefully studied,
notably by the illustrious Faraday, whose discoveries in connection
with magnetism and magneto-electricity have been briefly described.
The electric current was found to act as a most potent chemical force,
decomposing and recomposing many chemical compounds, dissolving and
depositing metals. Hence, early in the century arose the art of
electroplating of metals, such as electro-gilding, silver-plating,
nickel-plating, and copper deposition as in electrotyping. These arts
are now practised on a very large scale, and naturally have affected
the whole course of manufacturing methods during the century. Moreover,
since the introduction of dynamo current, electrolysis has come to
be employed in huge plants, not only for separating metals from each
other, as in refining them, but in addition for separating them from
their ores, for the manufacture of chemical compounds before unknown,
and for the cheap production of numerous substances of use in the
various arts on a large scale. Vast quantities of copper are refined,
and silver and gold often obtained from residues in sufficient amount
to pay well for the process.
At Niagara also are works for the production of the metal aluminum from
its ores. Similar works exist at other places here and abroad where
power is cheap. This metal, which competes in price with brass, bulk
for bulk, was only obtainable before its electric reduction at $25 to
$30 per pound. The metal sodium is also extracted from soda. A large
plant at Niagara also uses the electric current for the manufacture of
chlorine for bleach, and caustic soda, both from common salt. Chlorate
of potassium is also made at Niagara by electrolysis. The field of
electro-chemistry is, indeed, full of great future possibilities. Large
furnaces heated by electricity, a single one of which will consume more
than a thousand horse-power, exist at Niagara. In these furnaces is
manufactured from coke and sand, by the Acheson process, an abrasive
material called carborundum, which is almost as hard as diamond, but
quite low in cost. It is made into slabs and into wheels for grinding
hard substances. The electric furnace furnishes also the means for
producing artificial plumbago, or graphite, almost perfectly pure, the
raw material being coke powder.
A large amount of power from Niagara is also consumed for the
production in special electric arc furnaces of carbide of calcium
from coke and lime. This is the source of acetylene gas, the new
illuminant, which is generated when water is brought into contact
with the carbide. The high temperature of the electric furnace thus
renders possible chemical actions which under ordinary furnace heat
would not take place. Henri Moissan, a French scientist, well known
for his brilliant researches in electric furnace work, has even shown
that real diamonds can be made under special conditions in the electric
furnace. He has, in fact, probably practised in a small way what has
occurred on a grand scale in nature, resulting in diamond fields such
as those at Kimberley. One problem less is thus left to be solved. The
electro-chemical and kindred arts are practised not alone at Niagara,
but at many other places where power is cheap. Extensive plants have
grown up, mostly within the five years before the close of the century.
All of the great developments in this field have come about within the
last decade.
The use of electricity for heating is not confined to electric
furnaces, in which the exceedingly high temperature obtainable is the
factor giving rise to success. While it is not likely that electricity
will soon be used for general heating, special instances, such as the
warming of electric cars in winter by electric heaters, the operation
of cooking appliances by electric current, the heating of sad-irons and
the like, give evidence of the possibilities should there ever be found
means for the generation of electric energy from fuel with such high
efficiency as eighty per cent. or more. Present methods give, under
most favorable conditions, barely ten per cent., ninety per cent. of
the energy value of the fuel being unavoidably wasted.
Another application of the heating power of electric currents is
found in the Thomson electric welding process, the development of
which has practically taken place in the past ten years. In this
process an exceedingly large current, at very low electric pressure,
traverses a joint between two pieces of metal to be united. It heats
the joint to fusion or softening; the pieces are pushed together and
welded. Here the heat is generated in the solid metal, for at no time
during the operation are the pieces separated. The current is usually
obtained from a welding transformer, an example of an extreme type
of step-down transformer. Current at several hundred volts passed
into the primary winding is exchanged for an enormous current at only
two or three volts in the welding circuit in which the work is done.
The present uses of this electric welding process are numerous and
varied. Pieces of most of the metals and alloys, before regarded as
unweldable, are capable of being joined not only to pieces of the same
metal, but also to different metals. Electric welding is applied on
the large scale, making joints in wires or rods, for welding wagon and
carriage wheel tires, for making barrel-hoops and bands for pails,
for axles of vehicles, and for carriage framing. It has given rise to
special manufactures, such as electrically welded steel pipe or tube,
wire fencing, etc. It is used for welding together the joints of
steel car-rails, for welding teeth in saws, for making many parts of
bicycles, and in tool making. An instance of its peculiar adaptability
to unusual conditions is the welding of the iron bands embedded within
the body of a rubber vehicle tire for holding the tire in place. For
this purpose the electric weld has been found almost essential.
Another branch of electric development concerns the storage of
electricity. The storage battery is based upon principles discovered by
Gaston Planté, and applied, since 1881, by Brush, by Faure, and others.
Some of the larger lighting stations employ as reservoirs of electric
energy large batteries charged by surplus dynamo current. This is
afterwards drawn upon when the consumer’s load is heavy, as during the
evening. The storage battery is, however, a heavy, cumbrous apparatus,
of limited life, easily destroyed unless guarded with skill. If a
form not possessing these faults be ever found, the field of possible
application is almost limitless.
The above by no means complete account of the progress in electric
applications during the century just closed should properly be
supplemented by an account of the accompanying great advances regarded
from the purely scientific aspect. It is, however, only possible to
make a brief reference thereto within the limits of this article. The
scientific study of electricity and the application of mathematical
methods in its treatment has kept busy a host of workers and drawn
upon the resources of the ablest minds the age has produced. Gauss,
Weber, Ampère, Faraday, Maxwell, Helmholtz, are no longer with us.
Of the early founders of the science we have yet such men as Lord
Kelvin, formerly Sir William Thomson, Mascart, and others, still
zealous in scientific work. Following them are a large number, notable
for valuable contributions to the progress of electrical science,
in discoveries, in research, and in mathematical treatment of the
various problems presented. Modern magnetism took form in the hands
of Rowland, Hopkinson, Ewing, and many other able workers. Maxwell’s
electro-magnetic theory of light is confirmed by the brilliant
researches of the late Dr. Hertz, too early lost to science. Hertz
proved that all luminous phenomena are in essence electrical.
The wireless telegraphy of to-day is a direct outcome of Hertz’s
experiments on electric waves. It is but little more than ten years
since Hertz announced his results to the world. His work, supplemented
by that of Branly, Lodge, Marconi, and others, made wireless telegraphy
a possibility.
The wonderful X-ray, and the rich scientific harvest which has followed
the discovery by Röntgen of invisible radiation from a vacuum tube, was
preceded by much investigation of the effects of electric discharges in
vacuum tubes, and Hittorf, followed by Crookes, had given special study
to these effects in very high or nearly perfect vacua. Crookes, though
especially enriching science by his work, missed the peculiar X-ray,
which, nevertheless, must have been emitted from many of his vacuum
tubes, not only in his hands, but in those of subsequent students. It
was as late as 1896 that Röntgen announced his discovery. Since that
time several other sources of invisible radiation have been discovered,
more or less similar in effect to the radiations from a vacuum tube,
but emitted, singular as the fact is, from rare substances extracted
from certain minerals. Leaving out of consideration the great value
of the X-ray to physicians and surgeons, its effect in stimulating
scientific inquiry has almost been incalculable. The renewed study of
effects of electric discharge in vacuum tubes has already, in the work
of such investigators as Lenard, J. J. Thomson, and others, apparently
carried the subdivision of matter far beyond the time-honored chemical
atom, and has gone far towards showing the essential unity of all the
chemical elements. It is as unlikely that the mystery of the material
universe will ever be completely solved as it is that we can gain an
adequate conception of infinite space or time. But we can at least
extend the range of our mental vision of the processes of nature as we
do our real vision into space depths by the telescope and spectroscope.
There can now be no question that electric conditions and actions are
more fundamental than many hitherto so regarded.
The nineteenth century closed with many important problems in
electrical science unsolved. What great or far-reaching discoveries are
yet in store, who can tell? What valuable practical developments are
to come, who can predict? The electrical progress has been great—very
great—but after all only a part of that grander advance in so many
other fields. The hands of man are strengthened by the control of
mighty forces. His electric lines traverse the mountain passes as well
as the plains. His electric railway scales the Jungfrau. But he still
spends his best effort, and has always done so, in the construction and
equipment of his engines of destruction, and now exhausts the mines
of the world of valuable metals, for ships of war, whose ultimate
goal is the bottom of the sea. In this also electricity is made to
play an increasingly important part. It trains the guns, loads them,
fires them. It works the signals and the search-lights. It ventilates
the ship, blows the fires, and lights the dark spaces. Perhaps all
this is necessary now, and, if so, well. But if a fraction of the
vast expenditure entailed were turned to the encouragement of advance
in the arts and employments of peace in the twentieth century, can
it be doubted that, at the close, the nineteenth century might come
to be regarded, in spite of its achievements, as a rather wasteful,
semi-barbarous transition period?