Books: Marvels of Modern Science
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Paul Severing >> Marvels of Modern Science
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Down in the kitchen the cooking is carried on almost mechanically by
means of an electric clock controlling the heating circuits to the
various utensils. The cook, knowing just how long each dish will require
to be cooked, turns on the current at the proper time and then sets
the clock to automatically disconnect that utensil when sufficient
time, so many minutes to the pound, has elapsed. When this occurs a
little electric bell rings, calling attention to the fact, that the
heat has been shut off.
Another kitchen accessory is a rotating table on which are mounted
various household machines such as meat choppers, cream whippers, egg
beaters and other apparatus all electrically operated.
There is also an electric dishwasher and dryer and plate rack
manipulator which places the dishes in position when clean and dried.
The advantages of cooking by electricity are apparent to all who have
tested them. Food cooked in an electric baking oven is much superior
than when cooked by any other method because of the better heat
regulation and the utter cleanliness, there being absolutely no dust
whatever as in the case when coal is used. The electric oven does not
increase the temperature nor does it exhaust the pure air in the room
by burning up the oxygen. The time required for cooking is about the
same as with coal.
The perfect cleanliness of an electric plate warmer is sufficient to
warrant its use. It keeps dishes at a uniform temperature and the food
does not get scorched and become tough.
Steaks prepared on electric gridirons and broilers are really delicious
as they are evenly done throughout and retain all the natural juices
of the meat; there is no odor of gas or of the fire and portions done
to a crisp while others are raw on the inside. In toasting there is
no danger of the bread burning on one side more than on the other, or
of its burning on either side and a couple of dozen slices can be done
together on an ordinary instrument at the same time. The electric
diskstove, flat on the top, like a ball cut in two, can be also utilized
as a toaster or for heating any kettles or pots or vessels with flat
bottoms.
Very appetizing waffles are made with electric waffle irons, because
the bottom and top irons are uniformly heated, so that the irons cook
the waffles from both sides at the same time.
Electric potato peeling machines consist of a stationary cylinder
opened at the top for the reception of the potatoes and having a
revolving disk at the bottom. The cylinder has a rough surface or is
coated with diamond flint, so that when the disk revolves the potatoes
are thrown against the sides of the cylinder and the skin is scraped
off. There is no deep cutting as when peeled by a knife, therefore,
much waste is avoided. While the potatoes are being scraped, a stream
of water plays upon them taking away the skins and thoroughly cleansing
the tubers.
Among other electric labor savers connected with the culinary department
may be mentioned floor-scrubbers, dish-washers, coffee-grinders, meat
choppers, dough-mixers and cutlery-polishers, all of which give
complete satisfaction at a paltry cost and save much time and labor.
A small motor can drive any of these instruments or several can be
attached and run by the same motor. The operation of an ordinary snap
switch will supply energy to electric water-heaters attached to the
kitchen boiler or to the faucet. The instantaneous water heater also
purifies the water by killing the bacteria contained in it.
The electric tea kettle makes a brew to charm the heart of a
connossieur. In fact all cooking done by electricity whether it is the
frying of an egg or the roasting of a steak is superior in every way
to the old methods and what accentuates its use is the cleanliness
with which it can be performed. And it should be taken into
consideration that in electric cooking there is no bending over hot
stoves and ranges or a stuffy evil smelling smoky atmosphere, but on
the contrary, fresh air, cleanliness and coolness which make cooking
not the drudgery it has ever been, but a real pleasure.
Let us take a glance at the laundry in the electrically equipped house.
There is a large tub with a wringer attached to it and a simple
mechanism by which a small motor can either be connected with the tub
or the wringer as required. The washing is performed entirely by the
motor and in a way prevents the wear and tear associated with the old
method of scrubbing and rubbing done at the expense of much "elbow
grease." The motor turns the tub back and forth and in this way the
soapy water penetrates the clothes, thus removing the dirt without
injuring or tearing the fabric. In the old way, the clothes were moved
up and down in the water and torn and worn in the process. By the new
way it is the water which moves while the clothes remain stationary.
When the clothes are thoroughly washed, the motor is attached to the
wringer and they are passed through it; they are completely dried by
a specially constructed electric fan. Whatever garments are to be
ironed are separated and fed to a steel roll mangle operated by a motor
which gives them a beautiful finish. The electric flat iron plays also
an important part in the laundry as it is clean and never gets too hot
nor too cold and there is no rushing back to replenish the heaters.
One is not obliged to remain in the room with a hot stove, and suffer
the inconveniences. No heat is felt at all from the iron as it is all
concentrated on the bottom surface. It is a regular blessing to the
laundress especially in hot weather. There is a growing demand in all
parts of the country for these electric flat-irons.
Electricity plays an important role in the parlor and drawing-room.
The electric fireplace throws out a ruddy glow, a perfect imitation
of the wide-open old-fashioned fireplaces of the days of our
grandmothers. There are small grooves at certain sections in the
flooring over which chairs and couches can be brought to a desired
position. When the master drops into his favorite chair by the fireplace
if he wishes a tune to soothe his jangled nerves, there is an electric
attachment to the piano and he can adjust it to get the air of his
choice without having to ask any one to play for him. In the
drawing-room an electric fountain may be playing, its jets reflecting
the prismatic colors of the rainbow as the waters fall in iridescent
sparkle among the lights. Such a fountain is composed of a small
electric motor and a centrifugal pump, the latter being placed in the
interior of a basin and connected directly to the motor shaft. The
pump receives the water from the basin and conveys it through pipes
and a number of small nozzles thus producing cascades. The water falling
upon an art glass dome, beneath which are small incandescent lamps,
returns to the basin and thence again to the pump. There is no necessity
of filling the fountain until the water gets low through evaporation.
When the lights are not in colored glass, the water may be colored and
this gives the same effect. To produce the play of the fountain and
its effects, it is only necessary to connect it to any circuit and
turn on the switch. The dome revolves by means of a jet of water driven
against flanges on the under side of the rim of the dome and in this
way beautiful and prismatic effects are produced. The motor is noiseless
in operation. In addition to the pretty effect the fountain serves to
cool and moisten the air of the room.
The sleeping chambers are thoroughly equipped. Not only the rooms may
be heated by electricity but the beds themselves. An electric pad
consisting of a flexible resistance covered with soft felt is connected
by a conductor cord to a plug and is used for heating beds or if the
occupant is suffering from rheumatism or indigestion or any intestinal
pain this pad can be used in the place of the hot water bottle and
gives greater satisfaction. There is a heat controlling device and the
circuit can be turned on or off at will.
There are many more curious devices in the electrically equipped house
which could they have been exhibited a generation or so ago, would
have condemned the owner as a sorcerer and necromancer of the dark
ages, but which now only place him in the category of the smart ones
who are up to date and take advantage of the science and progress of
the time.
CHAPTER XI
HARNESSING THE WATER-FALL
Electric Energy--High Pressure--Transformers--Development of
Water-power.
The electrical transmission of power is exemplified in everything which
is based on the generation of electricity. The ordinary electric light
is power coming from a generator in the building or a public
street-dynamo.
However, when we talk in general terms of electric transmission we
mean the transmission of energy on a large scale by means of overhead
or underground conductors to a considerable distance and the
transformation of this energy into light and heat and chemical or
mechanical power to carry on the processes of work and industry. When
the power or energy is conveyed a long distance from the generator,
say over 30 miles or more, we usually speak of the system of supply
as long distance transmission of electric energy. In many cases power
is conveyed over distances of 200 miles and more. When water power is
available as at Niagara, the distance to which electric energy can be
transmitted is considerably increased.
The distance to a great extent depends on the cost of coal required
for generation at the distributing point and on the amount of energy
demanded at the receiving point. Of course the farther the distance
the higher must be the voltage pressure.
Electrical engineers say that under proper conditions electric energy
may be transmitted in large quantity to a distance of 500 miles and
more at a pressure of about 170,000 volts. If such right conditions
be established then New York, Chicago and several other of our large
cities can get their power from Niagara.
In our cities and towns where the current has only to go a short
distance from the power house, the conductors are generally placed in
cables underground and the maximum electro-motive force scarcely ever
exceeds 11,000 volts. This pressure is generated by a steam-driven
alternating-current generator and is transmitted over the conductors
to sub-stations, where by means of step-down transformers, the pressure
is dropped to, say, 600 volts alternating current which by rotary
converters is turned into direct current for the street mains, for
feeders of railways and for charging storage batteries which in turn
give out direct current at times of heavy demand.
That electric transmission of energy to long distances may be
successfully carried out transformers are necessary for raising the
pressure on the transmission line and for reducing it at the points
of distribution. The transformer consists of a magnetic circuit of
laminated iron or mild steel interlinked with two electric circuits,
one, the primary, receiving electrical energy and the other the
secondary, delivering it to the consumer. The effect of the iron is
to make as many as possible of the lines of force set up by the primary
current, cut the secondary winding and there set up an electromotive
force of the same frequency but different voltage.
The transformer has made long distance the actual achievement that it
is. It is this apparatus that brought the mountain to Mohammed. Without
it high pressure would be impossible and it is on high pressure that
success of long distance transmission depends.
To convey electricity to distant centres at a low pressure would require
thousands of dollars in copper cables alone as conductors. To illustrate
the service of the transformer in electricity it is only necessary to
consider water power at a low pressure. In such a case the water can
only be transmitted at slow speed and through great openings, like
dams or large canals, and withal the force is weak and of little
practical efficiency, whereas under high pressure a small quantity can
be forced through a small pipe and create an energy beyond comparison
to that developed when under low pressure.
The transformer raises the voltage and sends the electrical current
under high pressure over a small wire and so great is this pressure
that thousands of horse-power can be sent to great distances over small
wires with very little loss.
Water power is now changed to electrical power and transmitted over
slender copper wires to the great manufacturing centres of our country
to turn the wheels of industry and give employment to thousands.
Nearly one hundred cities in the United States alone are today using
electricity supplied by transmitted water-power. Ten years ago Niagara
Falls were regarded only as a great natural curiosity of interest only
to the sightseer, today those Falls distribute over 100,000 horse-power
to Buffalo, Syracuse, Rochester, Toronto and several smaller cities
and towns. Wild Niagara has at last indeed been harnessed to the
servitude of man. Spier Falls north of Saratoga, practically unheard
of before, is now supplying electricity to the industrial communities
of Schenectady, Troy, Amsterdam, Albany and half a dozen or so smaller
towns.
Rivers and dams, lakes and falls in all parts of the country are being
utilized to supply energy, though at the present time only about
one-fortieth of the horse-power available through this agent is being
made productive. The water conditions of the United States are so
favorable that 200,000,000 horse-power could be easily developed, but
as it is we have barely enough harnessed to supply 5 million
horse-power.
Eighty per cent. of the power used at the present time is produced
from fuel. This percentage is sure to decrease in the future for fuel
will become scarcer and the high cost will drive fuel power altogether
out of the market.
New York State has the largest water power development in the Union,
the total being 885,862 horsepower; this fact is chiefly owing to
the energy developed by Niagara.
The second State in water-power development is California, the total
development being 466,774 horsepower over 1,070 wheels or a unit
installation of about 436 H.P.
The third State is Maine with 343,096 horse-power, over 2,707 wheels
or an average of about 123 horse-power per wheel.
Lack of space makes it impossible to enter upon a detailed description
of the structural and mechanical features of the various plants and
how they were operated for the purpose of turning water into an electric
current. The best that can be done is to outline the most noteworthy
features which typify the various situations under which power plants
are developed and operated.
The water power available under any condition depends principally upon
two factors: First, the amount of fall or hydrostatic head on the
wheels; second, the amount of water that can be turned over the wheels.
The conditions vary according to place, there are all kinds of fall
and flow. To develop a high power it is necessary to discharge a large
volume of water upon properly designed wheels. In many of the western
plants where only a small amount of water is available there is a great
fall to make up for the larger volume in force coming down upon the
wheels. So far as actual energy is concerned it makes no difference
whether we develop a certain amount of power by allowing twenty cubic
feet of water per second to fall a distance of one foot or allow one
cubic foot of water per second to fall a distance of twenty feet.
In one place we may have a plant developing say 10,000 horse-power
with a fall of anywhere from twenty to forty feet and in another place
a plant of the same capacity with a fall of 1,000, 1,500 or 2,000 feet.
In the former case the short fall is compensated by a great volume of
water to produce such a horse-power, while in the latter converse
conditions prevail. In many cases the power house is located some
distance from the source of supply and from the point where the water
is diverted from its course by artificial means.
The Shawinigan Falls of St. Maurice river in Canada occur at two points
a short distance apart, the fall at one point being about 50 and at
the other 100 feet high. A canal 1,000 feet long takes water from the
river above the upper of these falls and delivers it near to the
electric power house on the river bank below the lower falls. In this
way a hydrostatic head of 125 feet is obtained at the power house. The
canal in this case ends on high ground 130 feet from the power house
and the water passes down to the wheels through steel penstocks 9 feet
in diameter.
In a great many cases in level country the water power can only be
developed by means of such canals or pipe lines and the generating
stations must be situated away from the points where the water is
diverted from its course.
In mountainous country where rivers are comparatively small and their
courses are marked by numerous falls and rapids, it is generally
necessary to utilize the fall of a stream through some miles of its
length in order to get a satisfactory development of power. To reach
this result rather long canals, flumes, or pipe lines must be laid to
convey the water to the power stations and deliver it at high pressure.
California offers numerous examples of electric power development with
the water that has been carried several miles through artificial
channels. An illustration of this class of work exists at the electric
power house on the bank of the Mokelumne river in the Sierra Nevada
mountains. Water is supplied to the wheels in this station under a
head of 1,450 feet through pipes 3,600 feet long leading to the top
of a near-by hill. To reach this hill the water after its diversion
from the Mokelumne river at the dam, flows twenty miles through a canal
or ditch and then through 3,000 feet of wooden stave pipe. Although
California ranks second in water-power development it is easily the
first in the number of its stations, and also be it said, California
was the first to realize the possibilities of long distance electrical
energy. The line from the 15,000 horsepower plant at Colgate in this
State to San Francisco by way of Mission San Jose, where it is supplied
with additional power, has a length of 232 miles and is the longest
transmission of electrical energy in the world. The power house at
Colgate has a capacity of 11,250 kilowatts in generators, but it is
uncertain what part of the output is transmitted to San Francisco, as
there are more than 100 substations on the 1,375 miles of circuit in
this system.
Another system, even greater than the foregoing which has just been
completed is that of the Stanislaus plant in Tuolumme County,
California, from which a transmission line on steel towers has been
run in Tuolumme, Calaveras, San Joaquin, Alameda and Contra Costa
Counties for the delivery of power to mines and to the towns lying
about San Francisco Bay. The rushing riotous waters of the Stanislaus
wasted for so many centuries have been saved by the steel paddles of
gigantic turbine water wheels and converted into electricity which
carries with the swiftness of thought thousands of horse power energy
to the far away cities and towns to be transformed into light and heat
and power to run street cars and trains and set in motion the mechanism
of mills and factories and make the looms of industry hum with the
bustle and activity of life.
It is said that the greatest long distance transmission yet attempted
will shortly be undertaken in South Africa where it is proposed to
draw power from the famous Victoria Falls. The line from the Falls
will run to Johannesburg and through the Rand, a length of 700 miles.
It is claimed the Falls are capable of developing 300,000 electric
horse power at all times.
Should this undertaking be accomplished it will be a crowning
achievement in electrical science.
CHAPTER XII
WONDERFUL WARSHIPS
Dimensions, Displacements, Cost and Description of Battleships--
Capacity and Speed--Preparing for the Future.
All modern battleships are of steel construction. The basis of all
protection on these vessels is the protective deck, which is also
common to the armored cruiser and many varieties of gunboats. This
deck is of heavy steel covering the whole of the vessel a little above
the water-line in the centre; it slopes down from the centre until it
meets the sides of the vessel about three feet below the water; it
extends the entire length of the ship and is firmly secured at the
ends to the heavy stem and stern posts. Underneath this deck are the
essentials of the vessel, the boilers and machinery, the magazines and
shell rooms, the ammunition cells and all the explosive paraphernalia
which must be vigilantly safe-guarded against the attacks of the
enemy. Every precaution is taken to insure safety. All openings in the
protective deck above are covered with heavy steel gratings to prevent
fragments of shell or other combustible substances from getting through
to the magazine or powder cells.
The heaviest armor is usually placed at the water line because it is
this part of the ship which is the most vulnerable and open to attack
and where a shell or projectile would do the most harm. If a hole were
torn in the side at this place the vessel would quickly take in water
and sink. On this account the armor is made thick and is known as the
water-line belt. At the point where the protective deck and the ship's
side meet, there is a projection or ledge on which this armor belt
rests. Thus it goes down about three feet below the water and it extends
to the same distance above.
The barbettes, that is, the parapets supporting the gun turrets, are
one forward and one aft. They rest upon the protective deck at the
bottom and extend up about four feet above the upper deck. At the top
of the barbettes, revolving on rollers, are the turrets, sometimes
called the hoods, containing the guns and the leading mechanism and
all of the machinery in connection with the same. The turret ammunition
hoists lead up from the magazine below, delivering the charges and
projectiles for the guns at the very breach so that they can be loaded
immediately.
An athwartship line of armor runs from the water line to the barbettes,
resting upon the protective deck. In fact, the space between the
protective and upper deck is so closed in with armor, with a barbette
at each end, that it is like a citadel or fort or some redoubt
well-guarded from the enemy. Resting upon the water-belt and the
athwartship or diagonal armor, and following the same direction is a
layer of armor usually somewhat thinner which is called the lower
case-mate armor; it extends up to the lower edge of the broadside gun
ports, and resting upon it in turn is the upper case-mate armor,
following the same direction, and forming the protection for the
broadside battery. The explosive effect of the modern shell is so
tremendous that were one to get through the upper case-mate and explode
immediately after entering, it would undoubtedly disable several guns
and kill their entire crews; it is, therefore, usual to isolate each
broadside gun from its neighbors by light nickel steel bulkheads a
couple of inches or so thick, and to prevent the same disastrous result
among the guns on the opposite side, a fore-and-aft bulkhead of about
the same thickness is placed on the centre line of the ship. Each gun
of the broadside battery is thus mounted in a space by itself somewhat
similar to a stall. Abaft the forward turret there is a vertical armored
tube resting on the protective deck and at its upper end is the conning
tower, from which the ship is worked when in action and which is well
safe-guarded.
The tube protects all the mechanical signalling gear running into the
conning tower from which communication can be had instantly with any
part of the vessel.
To build a battleship that will be practically unsinkable by the gun
fire of an enemy it is only necessary to make the water belt armor
thick enough to resist the shells, missiles and projectiles aimed at
it. There is another essential that is equally important, and that is
the protection of the batteries. The experience of modern battles has
made it manifest, that it is impossible for the crew to do their work
when exposed to a hail of shot and shell from a modern battery of rapid
fire and automatic guns. And so in all more recently built battleships
and armored cruisers and gunboats, the protection of broadside batteries
and exposed positions has been increased even at the expense of the
water-line belt.
Armor plate has been much improved in recent years. During the Civil
War the armor on our monitors was only an inch thick. Through such an
armor the projectiles of our time would penetrate as easily as a bullet
through a pine board. It was the development of gun power and
projectiles that called forth the thick armor, but it was soon found
that it was impossible for the armor to keep pace with the deadliness
of the guns as it was utterly impossible to carry the weight necessary
to resist the force of impact. Then came the use of special plates,
the compound armor where a hard face to break up the projectile was
welded to a softer back to give the necessary strength. This was
followed by the steel armor treated by the Harvey process; it was like
the compound armor in having a hard face and a soft back, but the
plates were made from a single ingot without any welding.
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