I appear before you to give a short course of two lectures on the
application of electricity to lighting and working. To-night I shall
confine my attention entirely to lighting, and if we succeed in getting
through our subject, we shall devote ourselves next Wednesday to the
application of electricity for working tramways, to the transmission of
power for various purposes, and generally to working.
[5] Two juvenile lectures recently delivered before the Society of Arts,
London.--_From the Journal of the Society._
Many people imagine the electric light to be a cold light. It is a
delusion. It is called a cold light because in many of its forms it gives
what we may call a cheerless light; it has not got the warmth, the
comfortable look, of other artificial means of illumination.
The electric light owes its existence to the intense heat that the
electric current produces, and heat lies at the root of every system of
artificial illumination. For instance, suppose we take a common match and
light it, we light it simply because by the friction of the two surfaces
together we generate heat, the heat burns the substance of which the match
is made. We are able to light a common candle because we have applied heat
to the wick, the heat liquefies the wax of which the candle is made, the
wax is decomposed, it combines with the oxygen of the air, intense heat is
produced at that point, carbon is consumed, and the consequence is light.
So with all our various modes of artificial illumination. Gas, as you are
well aware, produces intense heat, and the result of that heat is light.
There are various ways in which gas is applied to produce heat and the
necessary consequence--light. Here is a Sellon gas burner, in which the
combustion of gas raises the temperature of a fine platinum cap, and the
result is, as you see, a very beautiful light. In one lamp we have a cap
or mantle, in the other case there is merely a flat disk gauze of
platinum. The combustion of the gas produces intense heat, which raises
the network to a very high state of temperature, though in the present
case the light is not so good as it should be, probably through the
pressure in the supply main not being sufficiently great.
In another case we have a gas jet surrounded with a network of some
vegetable matter, linen or cambric, steeped in a solution of salts of
zirconium, and a few other rare earths, and the intense heat of the gas
causes a very high temperature, and, as you see, a very brilliant effect
is produced.
You will see from this that in all cases of artificial illumination bodies
have to be raised to a high state of temperature. I hold in my hand a
piece of magnesium wire; it is really flat magnesium tape, but it is
called wire. If I heat that, you will observe that a very brilliant light
is produced, due to the very high temperature at which it burns. Now, if I
take a lump of coal and heat it--it requires to be raised to a certain
temperature before the oxygen is directed upon it--and subject it to a jet
of oxygen, you will see that it burns with very much more intense light
than you are accustomed to in the ordinary fire. If I take a piece of iron
wire and place it in a jar of oxygen, you see what a very brilliant effect
the combination of oxygen and iron produces through the iron being raised
to a very high temperature.
I have now shown you that in order to produce light we must, by some means
or other, raise the temperature of a body. But the high temperature that
we have to deal with is not that produced by the combination of the oxygen
of the air and carbon, and other bodies such as I have shown you, but it
is produced by the aid of the electric current. In all these cases the
result of the combustion you have seen has been to remove oxygen from the
air, but now I want to show you how a body can be raised to a high state
of temperature without combustion of any kind. In front of me I have a
fine platinum wire. In my hand I hold a wire that is in connection with a
battery upstairs, the other wire in connection with the battery is
attached to the far end of the fine platinum wire; now, when I make
contact with the near end of the platinum wire, you observe that the wire
is raised to redness, its temperature is high, and as I reduce the length
of the platinum wire it gets brighter and brighter, the amount of
electricity passing through it is greater and greater, and presently the
wire is fused. I should have pointed out that as the quantity of heat
generated in a wire increases, so does the color of the light. When heat
is applied to a body, that body is first warmed, then it gets gradually
hotter and hotter, until it becomes red hot, and the first color that
appears is always red. The temperature is further raised, and the body
assumes the color of orange, then at a little higher temperature it
appears yellow, and so the different colors of the rainbow are perceived
according to the different temperatures to which the body tested with is
raised. Now, I want to show you the most intense form in which heat can be
produced on this earth. There is no hotter object that we can obtain than
that of the electric arc. I will try and produce this arc. You observe
that when I bring these two pieces of carbon together, a current of
electricity passes between them, and the passage of the current of
electricity between them creates such an intense temperature that a
brilliant white light, as you see, is produced. Incandescent particles of
carbon pass between the two points, forming a sort of bridge or arch,
which is called the electric arc. But the temperature of this arc is, as I
said before, the highest temperature that we can produce; it has been
measured, and is found to be 8,500 deg. Fahr. That is a temperature that can
hardly be conceived; the melting point of iron is only about 1,200 deg. Fahr.;
the melting point of platinum, which is one of the most refractory metals
we have, is about 3,000 deg. Fahr.; but here in the arc we have the intense
temperature that nothing can withstand, equal to 8,500 deg. Fahr. The color is
really due to the combustion that takes place between the materials
forming the arc. I have just used two pieces of carbon, but I will now try
other materials--copper, iron, and zinc. You will see a difference in the
color of the light, due to the fact that metal is burned in the arc
instead of carbon. Every metal has its own distinct and particular color,
and the presence of the different metals can be detected by the character
of the small arcs produced.
I have shown you that we have two modes of producing intense heat, and
therefore light, by electricity. I want now to show you how we produce
electricity. The first essential for the production of electricity with a
hand machine like this is a good dinner. The energy provided by beef or
mutton enables the operator to turn the big wheel of the machine, whence
motion is transmitted to the apparatus for producing the electricity. This
machine when rotated causes a coil of copper wire to be whirled in a
magnetic field, and that rotation of the coil in a magnetic field converts
the energy derived from the grass and from the mutton through the machine
into electric currents; those electric currents flow through wires that
are under the table, they will appear in the two wires I hold in my hand,
and will, I hope, reappear in the little glow-lamps I have before me in
the shape of heat, and then of light when I attach the wires. The light of
the glow-lamp is of just the same form of energy as that which passed from
the sun to the earth, and by beginning backward from the lamps we have
light, heat, electric currents, mechanical motion, food or fuel in the
shape of mutton, grass on the South Downs, to the sun. Whichever way it is
taken, you will find there is direct action between the sun and the
glow-lamp. The lamps are now burning, and you see that we are able to
produce electricity to our hearts' content. Down-stairs there is a
gas-engine; the gas-engine is at work; the gas-engine works because the
gas supplies energy which, stored up in the bowels of the earth in the
form of coal for ages and ages, has been extracted; it has been converted
into gas at the large gas works down the River Thames, it has been brought
up here, it is burned in the gas-engine, and produces energy in the
gas-engine exactly in the same way as the mutton or beef produced energy
just now. There is a dynamo down-stairs exactly like the dynamo that we
have upon the platform, and the current that is produced is exactly as the
current we just obtained, and is sending electricity through all the lamps
in this room. The currents of electricity passing through the lamps are
producing intense heat, the heat is producing the incandescence of a fine
carbon filament, such as I will show you directly, and the consequence is
that we are now being lighted in this room by the energy that unmistakably
and undisputably arrived on this earth millions of years ago in the form
of sunshine.
We can store up the energy in batteries. I shall show you to-night two or
three different forms of battery. Here is what is called a primary
battery. The only difference between a primary battery and a secondary
battery is this, that a primary battery consists of chemical elements that
at once combine and produce electricity by combustion, whereas a secondary
battery involves some anterior electrical action, which prepares the
surfaces of two bodies to put them in exactly the same condition as a
primary battery. Here is a primary battery known as the Schanschieff,
which is charged with a solution of sulphate of mercury, and into that
sulphate of mercury we will dip plates of zinc and plates of carbon. Zinc
has a greater affinity for the sulphuric acid of the sulphate of mercury
than mercury has; the sulphuric acid will at once combine with the zinc;
it will burn the zinc just as the gas burned just now, but instead of
burning with heat and light in the battery, it burns in the form of
electricity, which appears in the glow-lamps attached. You see that the
moment the zinc and carbons are placed in the cell electricity is
produced, and the lamp is lighted. The form of battery from which we are
drawing our electricity to-night is the accumulator, or the storage or
secondary battery. The secondary battery simply consists of plates or
"grids," as they are called, one filled with litharge, and the other with
red lead; the one becomes pure lead, the other becomes peroxide of lead;
the plates are combined in this form, and then placed in a glass cell, and
upstairs there are 52 of these E.P.S. cells, which have been charged all
day long by the gas-engine of which I spoke, and which now contain a store
of electricity that I shall make considerable use of to-night before I
finish.
I showed you the form of electric light which we call the arc, and I have
here to-night two or three different forms of arc lamps, which I will show
in action. But I want you to see this arc light for yourselves, and I want
you to feel, as I feel, that in all nature there is nothing more wonderful
and nothing more beautiful than the action of electric currents in the
arc. The light is, as I attempted to show you, the very same light that
came from the sun. I can show you that it is of the same character as the
light of the sun, and in the lantern on the table there is an arc lamp the
light of which we will throw on the paper before me in the form of a
spectrum. There you see the spectrum in all its purity; the spectrum from
the sun is no purer as regards light than what you now see. There you see
all the colors of the rainbow, and I had intended, if it were possible, to
show you in the first experiment, in which we raised platinum wire to
incandescence, that the first color would be the red, then the orange,
then the yellow, then the green, then the blue, then the indigo, and
lastly the violet. Beyond the violet there are rays of light which we
cannot see; they are the rays that produce the photographic pictures, and,
had time permitted it, we would probably have taken to-night a picture by
means of the arc lamps, but it requires a long time to do so, and it
really is no more interesting than an ordinary photographic picture. There
are all the different colors of the rainbow. Those who are anxious to
remember the order of the colors can very easily do so if they will
remember this simple sentence, "Read over your good book in verse." The
first letter of each word in that sentence gives the first letter of the
color in the order of the spectrum. It would be a very good thing if some
of our artists were to study and remember the colors of the rainbow, for
it is an extremely rare thing indeed to find a picture with the colors of
the rainbow properly depicted, sometimes they are upside down, sometimes
they are mixed, and if you discuss the fact with an artist, he will say,
"I do not care about your science. I simply paint my own impressions."
I will now show you the arc in another form. We are to-night connected in
this room--I have told you there is a gas-engine down-stairs; there are
also secondary batteries upstairs--but we are in connection with the
Grosvenor Gallery in Bond Street. The Grosvenor Gallery has a central
station where a very large dynamo is at work, from which electricity is
supplied to different parts of London; many thousand lamps are fed, in a
great many clubs, theaters, and private houses; they are all lit up by the
currents generated underneath the Grosvenor Gallery. The Grosvenor Gallery
Company, through their engineer, Mr. Ferranti, have very kindly undertaken
to supply us to-night with a current. The current is supposed to be a very
dangerous one, in reality it is not; there is no electric current that has
ever been produced that is one-tenth as dangerous as a steam boiler, and
all these currents, however immense they may be, are very simply
controlled, and very easily brought within the region of safety. There is
no doubt that with the apparatus that is now being handled in this room,
if anybody were deliberately to put one wire in his mouth and the other in
his hand, he would have the funeral service performed over him in two or
three days; but those who know what they are about no more handle electric
light wires carelessly than they put their hands in a furnace or their
noses in boiling water. We acquire experience by practice, and we know by
this time pretty well how to deal with electric currents. Now, you see in
the lower arrangement there that safety catches are being put in, which
render any accident quite impossible. Passing through each of those boxes
there is what is called a "cut-out" safety fuse, or safety valve, and
should, from any accident, anything go wrong in this theater, or in any
way with the system outside the theater, the safety fuses would burst, and
would so remove all danger from inside. The switch has now been turned,
and by it the current from the Grosvenor Gallery has been brought within
our reach. You see an arc light produced by it, and you see how intensely
bright and brilliant that light is. I do not want you so much to see that
light itself, but I want you to see its projection, or picture; and if Mr.
Wickham will kindly direct it on that white paper, at the end of the room
furthest from the table, you will see a picture of the carbons which are
now emitting that intense and brilliant light. You will see that between
what appears to you as the top carbon (but which is in reality the bottom
carbon of the two) and the bottom one there is playing, apparently, a
shower of minute fragments of something, but which are in reality
innumerable minute flashes of lightning, there is a constant uninterrupted
shower of electric shocks passing, that produce that intense brilliancy,
and that very bright appearance. There is intense commotion, a terrible
surging about of matter in a molten condition. Well, that arc that you see
is produced by the currents from the Grosvenor Gallery. They are
alternating currents of electricity, currents that are constantly and
suddenly circulating backward and forward. The arc that we have at this
other end of the room is a direct current one, and it is now projected on
to another sheet of paper, where you see a different form of are
altogether. This arc is produced by the direct current from a battery. You
will see the form is quite different from that in the alternate current
arc. You heard a peculiar hissing sound just now; that is a peculiar
phenomenon in arc lamps that has attracted a good deal of attention from
physicists, but nobody has yet arrived at a satisfactory conclusion as to
the cause. The lamp sometimes sings and sometimes hisses, and while thus
behaving it produces an intense and variable inverse electro-motive force,
that has to be overcome before the current can produce a steady and silent
arc. You will notice in the upper carbon of this form of lamp a kind of
cup, or "crater." The lower carbon forms a kind of point, a raised
surface, and between the two there is on the projection that which appears
as a glow, but which in reality has very intense heat, reaching, as I told
you, a temperature of 8,500 deg. Fahr. In those two projections you have, I
think, within my experience for the first time, been shown in public an
alternate current arc and a direct current arc at the same time, so that
you are really able to see what I do not think most people have seen
before.
There are a great many different arc lamps. I have not time to bring
before you all the various lamps that I might have secured for your
inspection. There is the Brush lamp, that for a long time lit up the
streets of our city, and I sincerely hope very soon is going to light up
the city again. There was the Jablochkoff lamp, that lighted up our Thames
Embankment, and which can be seen, on going down the Strand, at the Tivoli
Restaurant, not far from here. The offices of the _Daily Telegraph_, in
Fleet Street, and many other places, are lighted up by different lamps,
many of them excellent. Our experience of the last two or three years at
the exhibitions has taught us that there are a great many different kinds
of arc lamps, but all these arc lamps are lamps so constructed that they
cause the pair of carbons to be fed, to be kept together, as they consume,
at the same rate as they do consume. The mechanism is of great delicacy,
it acts with great promptitude, and the one that we have here to-night is
one of the last and one of the best; it is known as the Brockie-Pell lamp.
The lamp now at work is a Brockie-Pell, and for those who are interested,
a diagram representing it is upon the wall, and its operation I shall be
very happy to explain after the lecture; it feeds with great rapidity,
with great convenience, and is one of the steadiest lamps we have.
There are objections to the arc light; it is extremely dazzling and
irritating to the eye. Although the arc lamps we have here to-night are of
the very best of their kind, and are certainly almost steady, still they
have little irregularities in their action, and worst of all, they throw
intense shadows. The light from them is not very well diffused, still the
light is very brilliant, and it raises the envy of a good many people. For
instance, the Brush Company were once establishing a light in the
neighborhood of Cork, and an Irish farmer was remarkably struck by the
appearance and the steadiness of the light, so he came to the engineer in
charge and asked him, as a great favor, if he could kindly tell him where
he got his oil from.
I must now go from this to the next branch, the glow-lamp, the lamp that
is burning so steadily and so nicely above us. For this lamp we do not use
platinum, such as I heated before you just now, but we use carbon, so fine
that although I have probably one hundred or more in my hand, they feel no
heavier than a feather. These extremely fine filaments of carbon are made
with very great care from cotton. I cannot show you the whole operation of
making carbons and some of the preliminary operations connected with the
making of the lamp; but owing to the kindness of the Anglo-American Brush
Company, their manager, Mr. Sillar, is here to-night, and we shall have
the pleasure of seeing how the whole operation of the manufacture of one
of these glow lamps, such as we have above us now, is carried out. The
carbons have already been formed, but the first process is that the cotton
fiber is carefully tied and wrapped around pieces of carbon, as you see.
It is then placed in a furnace and carbonized. After being thus prepared,
a glass tube of special quality selected for the purpose is used to form
the glass globe. Mr. Donaldson will take a piece of the glass tube before
you, and will blow it into the shape similar to the lamp I hold, which is
of the very familiar pear-like form. The carbon filament will then be
fixed in the glass bulb, the latter will be exhausted and sealed, and the
whole process be passed through before your eyes. I must first of all show
you why it is necessary to take all this care. We have in front of the
board one of these carbon filaments suspended, and we will now pass a
current through it, and the carbon filament is raised to incandescence, it
combines with the oxygen of the air, it is at once consumed, and, as you
saw, we only had a light for a few seconds. Now, in order to make that
light permanent, it is necessary to inclose the carbon filament in a glass
globe, and to exhaust from that glass globe all the air, or as much of it
as possible, and then, instead of having a life of a few seconds, the life
of a lamp frequently continues for 4,000 or 5,000 hours. The first
process, as I said, in making an incandescent lamp, after the carbon
filament has been prepared, is that of blowing a glass bulb. The blowpipe
has now been put on, and the intense heat of the Bunsen burner raises the
glass to incandescence, to a soft, plastic condition, so plastic that the
manipulator can do with it just whatever he likes. Having got the glass
to this particular shape, the filament will be placed inside it, first of
all mounting the filament, which is an operation requiring a great deal of
care and great skill in handling. It is an extremely pretty operation, and
I beg to call your attention to it. The carbon is fixed inside a fine
spiral of platinum, which is at the same time subjected to an intense
current which decomposes the oil or the hydrocarbon in which it is placed,
the carbon deposits on the carbon filament, and cements it to the platinum
spiral. That is called mounting the filament. When that is done, the
filament is fixed in the glass globe, and the platinum and glass are fused
together. The brilliance of the platinum can be seen during this
operation, and it is very pretty. I do not know how it would have been
possible for us to have glow-lamps if it had not been for the fact that
the coefficients or rates of expansion of platinum and glass are
practically exactly the same, and the result is that when the platinum and
glass are combined together, as they are in a glow-lamp, the two contract
and expand at the same rate, and the result is there is no leakage; if
there had been leakage through the glass, it would have been quite
impossible to have made a glow-lamp. The success of a glow-lamp depends
upon the vacuum produced, and the next process is to cement the lamp so
far to a vacuum tube connected to a mercurial air-pump. The one before you
is Mr. Lane Fox's. It would have been also impossible to have produced
these beautiful glow-lamps without the mercurial air-pump, so that the
success of electric lighting and its perfection depend upon, first, the
similarity of expansion of glass and platinum, and secondly upon our power
of producing a vacuum. As it takes ten minutes or a quarter of an hour to
carry out the process of exhaustion, I will proceed with other portions of
my subject, and presently, when the time is ready, Mr. Sillar will inform
me, and we will light up the lamp that has been made before you this
evening, and, I hope, with success. The operation we have just seen is one
that has been just as interesting to me as it has been to you. There are
very few who are permitted to see this operation. We once had it before in
this hall when General Webber read a paper on glow-lamps, but with that
exception I am not aware that the manufacture of glow-lamps has ever been
shown in public before. It is most wonderful to watch the marvelous way in
which glass can be twisted and turned to our ways and to our wants, and
the skill with which the blower is able to manipulate glass in its plastic
condition, and to shape it in any form he likes, is an operation which
never ceases to excite one's wonderment. The form of lamp that is being
made before us is of the ordinary size that we see used generally, but
there are a great many different sizes of glow-lamps. For instance, here
is a very small lamp; above me you will see, if I may call the small one a
dwarf, there is a giant glow-lamp. It is a lamp invented by the Honorable
Charles Parsons, it is made by the Sunbeam Lamp Company, of Gateshead, and
is called the Sunbeam lamp; it has the same proportion to an ordinary lamp
that an ostrich egg has to a hen's egg, and the light from it is of
equally large proportion, as you see now the current has been turned on to
it. It gives a light of four hundred candles, but it is rather too
brilliant I see by your faces, and we will go back to our old friends of
the ordinary size. There are also above us lamps of various sizes; there
is a five-candle, ten-candle, sixteen-candle, twenty-candle, and a
hundred-candle lamp. Here also are a fifty-candle Swan lamp, a
sixteen-candle Swan, and an eight-candle Swan lamp. There are the ordinary
sixteen-candle lamp; these are being burned from the Grosvenor Gallery.
Here is a miner's lamp, which is supplied with a current by the
Schanschieff battery, the same as I showed you at first. The peculiarity
of this arrangement is that when the battery is turned upside down the
light goes off, the zincs and carbons occupy one half of the cell, and the
solution the other half, the zincs and carbons being at the bottom, and
the battery is not excited unless contact is made with the carbons and
zinc. Such a battery as this will maintain its lamp for 12 or 13 hours.
There are several forms of the Schanschieff battery. Here is a portable
form, and lamp connected with it by a flexible wire, which can be used
when traveling; or in the night, when you want to know the time, you can
have a lamp and battery like this by your bedside, and you can turn it
upside down, and produce a light, see the hour, and turn the battery back.
These glow-lamps are used for different purposes and ways. They may be
used with care, they may be used recklessly; their duration depends a good
deal upon the care with which they are used. A practiced eye, one who is
accustomed to deal with electric lamps, can tell at a glance when the lamp
is raised to a proper incandescence; but there is a point in all lamps
that is a sign of danger, and indicates "breakers (or breakage) ahead."
Whenever in an electric light installation a glow-lamp begins to show a
blue effect, then breakers are ahead; the current must be reduced or other
steps taken. I want to show you this blue effect, which is extremely
pretty, and I want you to see the gradual stages through which a lamp
passes from long life to death, or rather to a very short and merry life.
We can make the life of a lamp just exactly what we like; we can make a
lamp last a minute, or we can make it last a hundred years, and the number
of years of its duration is simply dependent upon the current employed. I
have here a glow-lamp, and I pass a current through it. There is no blue
effect at present; the current is increased, and the carbon filament is
raised to a high state of incandescence. In such a state it would not last
for a long time, not more than ten minutes or a quarter of an hour; but it
does not show the blue effect yet. On further increasing the current the
blue effect appears, though I doubt whether it is visible to many of the
audience; a little more current is put on, and the blue effect is very
marked, the globe itself looks very brilliant, and--there--the current has
been increased until the filament has parted.
It is always better, when making an observation or experiment, to know
what you are going to see, so that you can direct your attention to
exactly what is being done or to what you want to know. If I put another
lamp through the same experiment, you will be better able to understand
this blue effect, and see just that point where the lamp is about to give
out. The current is now on, and is being gradually increased; the lamp is
now intensely blue, and--there--it has gone in the same way exactly as the
other one did. The way in which lamps burst is sometimes very beautiful;
they disintegrate, they seem to volatilize, and the substance of the lamp
is projected with great force against the side of the globe. On the table
there are several beautiful specimens showing this effect.
The glow-lamp in process of manufacture before you is now being unsealed
from the pump; it is now exhausted, and we will pass a current through it
so as to raise it to incandescence. The current is now on, and you see the
lamp burns with full brilliancy. The next experiment is rather a cruel
one, because it is willful destruction. I will not destroy the lamp that
has just been made before us, for I will keep it as a memento of this
evening. I want to show the safety of the electric lamp. Many people
imagine that there is a great deal of danger about it. I will take a
handkerchief, and in it place a lighted lamp, when, on the globe being
broken, the carbon filament instantly goes out, and there is no damage to
the handkerchief, or the slightest appearance of scorching or heating upon
it. On breaking that lamp you heard a report. That is due to the vacuum,
which, on sudden rupture, the air rushes in to fill. These lamps will not
only burn in air, but will actually burn in water. Here I have a lamp
which on placing in a bowl of water continues alight in the water just as
well as in the air. You can imagine what an immense boon that is to our
divers and others who unfortunately have to work under water for our
benefit.
I will not attempt to occupy your time in speaking of the beauties of this
wonderful light, how it removes really poison from our air, how it is very
good for sore eyes, because it burns with such steadiness that those who
work under it really never find, in any shape or form, any inconvenience
or discomfort to the eyes. It is extremely cleanly; it does not fill the
air we breathe with noxious fumes. People are little aware of it, but it
is a very simple calculation to show that thirty gas burners produce a
gallon of water in an hour, so that if you have thirty burners in a shop,
for instance, alight for six hours, six gallons of water are produced and
the water can very often be seen running down the cold windows of shops.
That water absorbs sulphur and sulphuric acid, and when deposited on books
and decorations destroys them. If we could only get the electric light
cheap, delivered at our doors, then everybody who has an idea of luxury
and comfort would at once take it.
I want now to show you some of the dodges of the electric light. First I
will show you that by the action of a cut-out an excess of current is
prevented from injuring the lamps. A cut-out is inserted so as to protect
a group of lamps here, and on a large current being sent you hear a crack,
and the lamps have gone out; the safety fuse has perished in performing
its duty. To prove this we will renew the cut-out, and on the proper
current being turned on, you see the lamps are sound. Here is an electric
cigar lighter. I raise this up and the wire in front of it comes to a
state of incandescence, and I have there, as you see, sufficient heat to
light my cigarette. Some years ago, I had my daughter's doll house, which
was furnished by herself, fitted up with the electric light, and I thought
that some of my younger hearers to-night, who were still in the doll age,
would appreciate the way in which a doll's house can be lighted up by
electricity. You now see the doll's house illuminated; it has a hall door
lamp which lights up on the opening of the door; the house has rooms
furnished, occupied with handsome dolls, and fitted with every kind of
contrivance; the doll who occupies the drawing room has the convenience of
a portable lamp, which she can move about wherever she likes, and each
room and the kitchen has a particular form of lamp.
I have also here a model of that famous ship the Captain, which was
wrecked off Cape Finisterre. The model has been fitted with electric
light, and you now see the mast head-light, the red light for the port
side, and the green light for the starboard side; there are high jinks
going on in the saloon by the aid of the electric light, and there is also
a search light which can be used for looking for the advance of the enemy.
A beautiful phosphorescent effect is produced upon the water, which is
covered with blue cotton wool, in which a lamp is placed, causing really a
very pretty illustration of what the phosphorescence of the sea is like.
Here I have an apparatus for heating curling tongs by electricity; here is
a flat iron treated in the same way, and here is a kettle in which the
current is carried to boil water. I travel a good deal, and I always carry
in my traveling bag a battery like this, which is one of Pitkin's
secondary batteries; it is light and extremely convenient. I can strap it
on my shoulder like an opera glass. To this is attached a reading lamp
which I fix in my waistcoat, and to the astonishment of my fellow
travelers, when the shades of evening are beginning to set, I take out the
lamp and put it in operation--so. My reading lamp is thus provided, and it
is fixed in the most convenient position, for the light falls just where
it is wanted, it does not offend the eye, and enables me to read the
smallest print. I have always got with me my own light, perhaps much to
the annoyance of my fellow passengers, and with the electric light
machinery at my own house, I have little or no trouble in recharging the
battery, or keeping it in order. The Pitkin battery is also applied to a
miner's lamp.