HOW TO EXPERIMENT
The kind of experimenting you will do will, of course, depend
altogether on the nature of the invention on which you are working.
But, as good fortune would have it if you are not mechanically inclined
you are not apt to hit upon a mechanical invention. And if you know
nothing of electricity, you are not likely to think out an improved
electrical device.
But this much is certain if you are going to experiment the right way
you must know something about the right way to experiment. No one
should expect to work out to a successful conclusion a new machine or
apply a new improvement to an old machine if he knows nothing of the
_first principles of mechanics_ or _about mechanical movements_, and by
rights he ought to have some knowledge of _machine design_.
And the above statement is just as true of electrical inventions. A
worker who does not know the difference between a binding post and
an alternating current need not expect to progress very far with an
invention of, say, an electric block signal system--unless he calls in
an expert to help him; but what he should do is to study the principles
of electricity and magnetism, learn the various currents that can be
used and what apparatus and instruments are needed for utilizing these
currents.
The same thing applies to inventions in chemistry in that to work
intelligently you must know about the properties of substances,
chemical change and acids, bases and salts. And with electro-chemistry
both a knowledge of chemistry and electricity are needed.
It is easy to see that it would not be possible in the limited space
I have here to say more than a word or two about the subjects of
mechanics, electricity, chemistry and electro-chemistry when each
requires a whole chapter to explain it even in a rough way and a whole
book to explain it thoroughly. But there are a few things I can tell
you about them that will put you on the right track and then I shall
give you the names of some books that will be of great service to you
when you are in need of them, and with your help we’ll make a real
inventor of you.
~How to Experiment with Machines.--~Any one who possesses the
slightest bent for mechanics can work out improvements on devices like
egg-beaters and monkey-wrenches and feel their way as they go along.
But when it comes to designing and building real machines where
numerous levers, gears, and springs are combined to make a working
unit you should by all means read up on the subjects of _work, energy
and power_, learn about the _six mechanical powers_--and the action of
machines in general. The following definitions will give you an idea
about all of them.
~Work, Energy and Power.--~A wheel will not turn of its own accord but
if it is moved round by some _force_ applied to it such as the hand, a
coiled spring or a motor, _work_ is done. In fact whenever a thing is
made to change its position work is done.
The power to do work is caused by _energy_; energy is developed when
some force is applied and can be stored up in bodies as when a ball
is thrown. When the energy stops acting, or is used up, there can no
longer be any work done. Energy can be _transferred_ from one body
to another, as from a clock-spring to a wheel, or from one wheel to
another wheel; and energy can be _transformed_, as the chemical energy
of a battery into the rotary energy of a motor or from steam into
mechanical motion.
The _unit of work_ is the _foot-pound_ and this is the work done to
raise _one pound one foot high_. The _rate_ of doing work is the _horse
power_ and a horse power is equal to lifting 550 foot-pounds in a
second, or 33,000 foot-pounds in a minute.
Energy may be either _potential_ or _kinetic_; _potential energy_ means
energy that is stored up and with nothing to act on, and for this
reason it is called _energy of position_. The electric charge of a
Leyden jar is potential energy but the moment it is released it makes
a spark and becomes _kinetic energy_ or _energy of motion_. Potential
energy can be changed into kinetic energy and kinetic energy back again
into potential energy with amazing freedom. Energy has a definite
relation to _velocity_ which means that when the speed of a moving
body is increased its power to do work is also increased.
Like matter, energy cannot be destroyed, and so all of it taken
together is called a _constant quantity_. When the energy stored up
in a spring, or a battery, has been used the energy is not destroyed,
though it may be very hard to find out where it has gone, but you may
know that it has vanished in heat and in other forms of energy.
~Work Against Friction.--~The chief resistance which machines have
to overcome is caused by _friction_. Since there is no such thing as
a perfectly smooth surface friction is always present in machines
and much energy must be spent in overcoming it. The energy wasted by
friction is not destroyed but is transformed into another kind of
energy and that is heat. When a marble is rolled over the surface of
a table there is less friction between the two than when the marble
slides across the table. Hence with _ball bearings_ there is less
friction than with _cone bearings_. (See Appendix I.)
~Forms of Energy.--~There are nine forms of energy that you can make
use of in your experiments and in your inventions, and these are:
{ Bodies in Motion--kinetic.
{ Bodies under Stress {
ENERGY OF MASSES { (like a coiled spring). { Potential.
{ Bodies attracted by {
{ Gravitation. {
{ Sound--both kinetic and potential.
{ Heat.
ENERGY OF MOLECULES { Molecular and Atomic Energy.
AND ATOMS { Chemical Action.
ENERGY OF ETHER { Electric and Magnetic Actions.
{ Light and Invisible Radiation.
~Machines and the Principles of Machinery.--~A _machine_ is a
contrivance of mechanical parts by which energy is transferred from
one part to another. Beside the amount of energy required for doing
useful work there must be an extra amount for overcoming the friction.
Remember that no machine can either create energy or increase it,
and, as you have seen, every machine wastes some energy in friction;
this being true it must be clear then that it is impossible to make a
machine which when once set in motion would continue to run forever, or
at least until its parts were worn out. So don’t waste _your energy_ in
trying to invent a _perpetual motion_ machine.
~The Uses of Machines.--~These are many and varied from a commercial
point of view in that they are designed to do better, faster or cheaper
work and sometimes all of these good qualities are found in a single
machine.
From a mechanical point of view, though, a machine is used to
(1) Change one form of energy into another form, as steam into
electricity.
(2) To make a slow moving, but powerful force produce a high speed or
velocity, as in a sewing machine.
(3) To change a small, fast moving force into a powerful force, as in
the action of a crowbar.
(4) To change the direction of a force so that the power can be
applied where and when it is needed, and
(5) To make use of whatever force is at hand as the strength of
animals, wind, water, steam, gas and electricity.
~The Six Mechanical Powers.--~As a matter of fact there are really only
two of these, namely the _lever_ and the _inclined plane_, the other
four, that is the _wheel_ and _axle_, the _pulley_, the _wedge_ and the
_screw_ being simply modified forms of the first two.
[Illustration: FIG. 37A. A LEVER OF THE FIRST CLASS]
[Illustration: FIG. 37B. A PAIR OF PLIERS]
The _lever_ is a rigid bar resting on, and which can be moved about a
fixed point, called the _fulcrum_. There are three classes of levers
and these are:
[Illustration: FIG. 38A. A LEVER OF THE SECOND CLASS]
[Illustration: FIG. 38B. A PAIR OF WIRE SPLICING CLAMPS]
(1) Where the fulcrum is placed between the load and the power which
moves it, as shown at A, Fig. 37; a pair of shears, pliers, a balance
and a crowbar are levers of the first-class, see B, Fig, 37.
[Illustration: FIG. 39A. A LEVER OF THE THIRD CLASS]
[Illustration: FIG. 39B. A PAIR OF SUGAR TONGS]
(2) Where the load is applied between the power and the fulcrum, as
shown at A, Fig. 38; a lemon squeezer and wire splicing clamps are
examples of this class; see B, Fig. 38, and
[Illustration: FIG. 40. A BENT LEVER]
(3) Where the power is applied between the load and the fulcrum as
shown at A, Fig. 39; the foot treadle of a jig saw and sugar tongs are
levers of this class. See B, Fig. 39. Then there is the _bent lever_,
as shown in Fig. 40, where the power and load do not act parallel
with each other, and the _compound lever_ which takes the place of
a single long lever as shown in Fig. 41, and which is used in large
platform-scales.
[Illustration: FIG. 41. A COMPOUND LEVER]
The _wheel_ and _axle_ is really a form of lever and fulcrum. The axle
provides a continuous fulcrum as shown in Fig. 42. Trains of wheel
work, such as are used in clocks and other mechanical devices, are
used to change a slow moving powerful force into a high speed, or
velocity, or the other way about. Fig. 43 shows a train of wheel work.
[Illustration: FIG. 42. THE WHEEL AND AXLE IS A MODIFIED LEVER
The power is applied at A, the weight is at B, and the Fulcrum is at C.]
[Illustration: FIG. 43. A TRAIN OF WHEELS OR WHEEL WORK]
The _pulley_ is a wheel with a cord, rope or belt running round it as
shown in Fig. 44. It is used to transmit power and also to change the
direction of it. A pulley can be either fixed or movable. A _compound
pulley_ makes it possible to raise a heavy weight with a very small
force, not by increasing the energy, but by transposing _velocity_ into
_power_.
[Illustration: FIG. 44. A FIXED PULLEY]
[Illustration: FIG. 45A. AN INCLINED PLANE]
[Illustration: FIG. 45B. ONE OF THE USES OF AN INCLINED PLANE]
The _inclined plane_ is any hard smooth surface set at a slant to the
force to be overcome. A barrel can be rolled up an inclined plane
against the force of gravity, as shown in Fig. 45, while it could not
be lifted straight up to the same height.
The _wedge_ is simply an inclined plane on a small scale. It is useful
where a great force must be exerted through a small distance, as in
splitting a stick of wood, as shown in Fig. 46.
[Illustration: FIG. 46A. A SIMPLE WEDGE]
[Illustration: FIG. 46B. TWO WEDGES FORM A PRINTER’S QUOIN]
A _screw_ is also a modified form of an inclined plane. By means of a
screw great pressures can be exerted in a small space and here again
a powerful force is had with a corresponding loss of velocity. It is
shown in Fig. 47.
[Illustration: FIG. 47A. THE THEORY OF A SCREW]
[Illustration: FIG. 47B. A SCREW CLAMP]
~Compound Machines.--~Any of the above six simple machines can be
combined with any or all of the others and every machine that has ever
been invented for any purpose is made up of a combination of these six
mechanical powers.
Since the beginning of invention there has been made by combining these
six mechanical powers in different ways, a large number of simple
machines called _mechanical movements_; and there has not been a single
new mechanical movement invented in many years.
Hence when you begin to work on your machine don’t waste time and
energy trying to devise the mechanical movement you need, or what is
still more foolish attempting to invent a new mechanical movement but
look at the pictures in Fig. 48 which gives over 60 of the most useful
mechanical movements. If you cannot find one among them that will do
the work then look for it in Gardner D. Hiscock’s book of _Mechanical
Movements_ which gives them all.
~Books.--~And it would be a good idea for you to read one of the
following books which you can, most likely, get at any library:
_Elementary Physics_: Elroy M. Avery.
_Elements of Physics_: Edwin J. Houston.
_Elements of Physics_: George H. Hoadley.
_College Physics_: A. L. Kimball.
The first-named books go deeply enough into the subject of physics for
all ordinary purposes while the last named is very thorough and has
a lot of _math_ in it; and all of them treat of liquids, air,
electricity and magnetism, sound, heat and light. In whatever field you
are working a general knowledge of physics will give you the key to a
new and a mighty interesting world.
[Illustration: FIG. 48A. SOME USEFUL MECHANICAL MOVEMENTS]
[Illustration: FIG. 48B. USEFUL MECHANICAL MOVEMENTS]
[Illustration: FIG. 48C. USEFUL MECHANICAL MOVEMENTS]
[Illustration: FIG. 48D. USEFUL MECHANICAL MOVEMENTS]
With the first principles of mechanics well in mind and the mechanical
movements I have given, you can go on with your experiments in a safe
and sensible way.
~How to Experiment with Electricity.--~_Electricity_ is very much like
mechanics in that any one can put up an electric bell or screw in a
plug-fuse but to experiment and build an apparatus in which electricity
and magnetism are the powers used you must know how electricity
is generated, how magnetism is produced, the different forms of
electricity that are available and finally the kinds of apparatus best
suited for the work that is required of them.
~Forms of Electricity.--~Though there is only one kind of electricity
it can be divided into four classes, or forms, and these are:
(1) Electricity at rest, or _static electricity_, that is electricity
stored up but not active as in a charged Leyden jar.
(2) Electricity in locomotion, or _current electricity_, in which
electricity flows along wires, through solutions and other conductors
when it is able to do work.
(3) Electricity in rotation, or _magnetism_ in which electric whirls
produce attraction and repulsion, and:
(4) Electricity in vibration, or _radiation_ in which electric
charges moving to and fro millions of times a second set up waves in
the _ether_ which our eyes can see and which we call _light_. Then
there are waves much too short for the eye to see and these are called
_ultra-violet_ waves; there are waves too long for the eye to see and
these are the _infra-red_ waves which we can feel for they are _heat_
waves, and finally there are very long waves set up in the ether
by surging _high frequency_ currents in wires and these are called
_electric_ or wireless waves.[2]
~Static Electricity.--~You can think of electricity as being a fluid,
like water, for it has both _quantity_ and _pressure_, and in many ways
it acts like a fluid.
If you filled a tank, raised above the ground, with water, the latter
would be at rest, but it would be under pressure too and the moment a
hole was bored in any part of the tank below the level of the water it
would squirt out; in other words the _potential water_ would be changed
into _kinetic_ water or water in locomotion. If, now, you charge a
_Leyden jar_, or a _condenser_, with electricity it will be at rest
until you bring the alternate coatings of tin-foil closely together
when a spark will result and a current will flow.
Static electricity is generated by _friction_ and by _induction_, but
the electricity so produced is very small in quantity and very high in
pressure. A Leyden jar, or other condenser can be charged, though, with
a low pressure current of electricity, as in a _spark coil_.
~Current Electricity.--~Whenever electricity flows in a wire, or other
conductor, it acts like water flowing through a pipe and it is then
called _current electricity_. The two most common ways to generate a
current of electricity is by means of a _chemical battery_ and by a
_dynamo electric machine_.
A current of electricity may have a small _current strength_, as its
quantity is called, and a high _voltage_, as its pressure is called,
like the discharge of a Leyden jar, or it may have a large current
strength and a low voltage, as a current generated by a battery.
A _direct current_, see Fig. 49, is a current which flows steadily
in one direction and this can be generated by a battery or a dynamo.
An _interrupted current_, see Fig. 50, is a current that is _made_
and _broken_ a number of times a minute and this is usually done by
a _vibrator_, or _interruptor_ as it is often called. A _pulsating
current_, see Fig. 51, is one whose current strength is varied. One
way to produce a pulsating current is to talk into a _telephone
transmitter_ which is connected with a battery.
[Illustration: FIG. 49. A STEADY DIRECT CURRENT]
[Illustration: FIG. 50. AN INTERRUPTED DIRECT CURRENT]
[Illustration: FIG. 51. A PULSATING DIRECT CURRENT]
An _alternating current_, see Fig. 52, is one which flows first in one
direction and then in the other direction. A _magneto-electric machine_
and an _alternating current generator_ are the means for generating
this form of current. Alternating current can be produced from a direct
current by using an _induction coil_, or _spark coil_ as it is called.
But a steady direct current can be obtained from an alternating current
only by coupling an _alternating current motor_ to a _direct current_
dynamo.
[Illustration: FIG. 52. AN ALTERNATING CURRENT]
The pressure, or voltage, of an alternating current can be _stepped
up_ or _stepped down_, that is, raised or lowered, by means of a
_transformer_, which is the simplest form of induction coil. The
current strength varies proportionately with the charges in pressure
so that there can never be any increase in the total amount of energy
but there is always a loss of energy due to heating and other causes.
The moral again is that an electrically driven perpetual motion
machine is a delusion and a snare. Alternating current can be changed
into _interrupted direct current_, see Fig. 53, by an _electrolytic
rectifier_ or a _mercury vapor tube_.
[Illustration: FIG. 53. ALTERNATING CURRENT CHANGED INTO AN INTERRUPTED
DIRECT CURRENT]
A _high tension current_ is an alternating current of sufficient
pressure to make a _jump-spark_; it can be produced by a _high-tension
magneto_, or a _spark coil_. An alternating current is generally
considered one that changes its direction less than 100,000 times a
second; when it changes its direction 100,000 times or more a second it
is called an _oscillating current_, see Fig. 54, or a _high frequency
current_, and this is the form of current that is used for sending out
_wireless waves_.
[Illustration: FIG. 54. A PERIODIC OSCILLATING CURRENT]
The only known way to set up oscillating currents of really high
frequency is by discharging the stored up electricity of a condenser,
or its equivalent, through a circuit of small resistance by means of a
spark, or an arc. The latter sets up sustained oscillations as shown in
Fig. 55. _High frequency alternators_ (machines) have been built which
generate alternating currents of over 100,000 _cycles_ per second.
[Illustration: FIG. 55. A SUSTAINED OSCILLATING CURRENT]
~Magnetism.--~A bar of steel can be made magnetic by rubbing it on a
_permanent steel magnet_ or on an _electromagnet_, or winding a number
of turns of wire around it and passing a current through the wire.
If a bar of soft iron is placed in a coil of wire and a current is made
to flow round it the iron will become a magnet but remains so only
while the current is flowing, and this forms an _electromagnet_. An
electromagnet works best on a direct current but an alternating current
can also be used to energize it.
A coil of wire with an _air core_, that is without either an iron or
a steel core, becomes a magnet when a current is made to flow through
it. If, now, one end of a bar of soft iron is slipped into the hole in
the coil of wire and the current is turned on the iron bar, or core,
will be drawn into it. This kind of a magnet is called a _plunger
electromagnet_, or _solenoid_.
~Radiation.--~Whenever you light a match, or make a light by any other
means, electric charges on the molecules of the substance which is
heated vibrate violently to and fro and the minute surgings of the
electric charges set up _electro-magnetic_ waves in the _ether_ which
the eye can see and the brain can sense and this is what we call
_light_.
When some substances are intensely heated, as for instance, the
_carbons_ of an _arc lamp_, waves are also sent out which are too short
for the eye to see but which will nevertheless affect a photographic
plate. These are called _ultra-violet waves_. The _infra-red_ waves are
too long for the eye to see but the nerves of our bodies sense them as
heat.
[Illustration: FIG. 56A. SOME USEFUL ELECTRO-MECHANICAL DEVICES]
[Illustration: FIG. 56B. SOME USEFUL ELECTRO-MECHANICAL DEVICES]
In conclusion take this bit of advice: don’t try to invent
a new kind of electric current and don’t try to devise a new
_electro-mechanical movement_ for in either case you will waste your
time. Every form of current and every kind of electro-mechanical device
you will need for any machine which you may invent are at hand and
ready for use. Fig. 56 shows a number of electro-mechanical devices and
these will aid you in getting the result you want.
~Books.--~The books on physics listed on page 69 go deeply enough into
the subject of static and current electricity and magnetism for all
ordinary purposes of invention, but if you are interested in _wireless_
and _high frequency electricity_ then I would suggest that you read the
following books:
_The Book of Wireless._ A. F. Collins.
_Manual of Wireless Telegraphy._ A. F. Collins.
_Wireless Telegraphy and High Frequency Electricity._ H. LaV. Twining.
_Electric Wave Telegraphy._ J. A. Fleming.
[Illustration: FIG. 57. AN AMMETER FOR MEASURING CURRENT]
[Illustration: FIG. 58. A VOLTMETER FOR MEASURING PRESSURE]
~Your Electrical Equipment.--~Should your invention call for
experiments in electricity, especially where the amount of current used
is a factor, you should provide yourself with a good _ammeter_, as
shown in Fig. 57, for measuring the current in _amperes_, and a _volt
meter_, as shown in Fig. 58, for measuring the pressure, or _voltage_,
in _volts_. (See Appendix O.)
Where the resistance in _ohms_ of a wire, or a circuit of any kind must
be known a _combined bridge and resistance box_ is the best way to
make accurate measurements. Resistance boxes measuring from .001 ohm
to 17.600 ohms can be bought of the L. E. Knott Apparatus Co., Boston,
Mass., for about $18.00. It is shown in Fig. 59.
[Illustration: FIG. 59. A RESISTANCE BOX FOR MEASURING THE RESISTANCE
OF WIRES]
A large number of electrical devices call for winding wire on cores,
spools, coils, etc. Nearly all windings can be done on a lathe but if a
lathe is not among your treasured possessions you can make a _winder_
which will serve all ordinary purposes. The drawings shown at A and B,
Fig. 60, give all the details of construction and you can make one
chiefly of wood of whatever size your winding calls for.
[Illustration: FIG. 60. AN EASILY MADE WINDING DEVICE
A. A side view
B. An end view]
~How to Experiment with Chemistry.--~It is a pleasant pastime to make
chemical experiments after a known formula but it is quite a different
and a difficult thing to try to invent some new chemical compound when
you know little or nothing of chemistry.
If your invention calls for some _chemical combination_ or
_decomposition_ or _double decomposition_--these are the three kinds
of chemical action--get an elementary book on chemistry and study it
until you really know it and then you will have a bed-rock foundation
on which to build up your invention.
You may say it is all very well to read a book on chemistry and learn
all about it but it’s a mighty hard thing to do without a teacher. My
answer is if you are not interested in chemistry, you will certainly
find the study of it up-hill work and very tedious.
But if you are working on an invention like, say, _synthetic
gems_, that is making real rubies and sapphires and emeralds in an
oxy-hydrogen furnace, see Fig. 61, you will not only study but you
will study harder than you have ever studied before if you believe it
will help you to find the solution of the gem problem. It is under
these conditions that work-study becomes play-study and you will
be fascinated with it and it will then prove pleasant as well as
profitable.
[Illustration: FIG. 61A. MAKING A REAL RUBY BY CHEMISTRY]
[Illustration: FIG. 61B. RUBY BOULES AS THEY COME FROM THE FURNACE]
[Illustration: FIG. 61C. SYNTHETIC RUBIES AFTER THEY ARE CUT]
~Your Chemical Equipment.--~The chemical apparatus you will require
depends entirely on the class of work you are doing but for all
ordinary chemical experiments the following apparatus will be found
useful: (1) a nest of beakers; (2) a jeweler’s blowpipe; (3) one-half
dozen wide mouth flint bottles; (4) a Bunsen burner with regulator,
that is if you have gas, or (5) an alcohol lamp; (6) a glass U tube;
(7) a nest of Hessian crucibles; (8) a nest of porcelain crucibles; (9)
an evaporating dish; (10) a lead dish; (11) a couple of glass funnels;
(12) a glass bottle with a two hole stopper; (13) half a pound of glass
tubing; (14) a porcelain mortar and pestle; (15) a plain glass retort;
(16) a stoppered retort; (17) 3 or 4 feet of ¼ inch rubber tubing; (18)
a sand bath; (19) a dozen test tubes; (20) a test-tube stand; (21) a
test-tube clamp; (22) a test-tube brush; (23) an iron retort tripod;
(24) one-half dozen watch glasses; (25) a water bath; (26) some wire
clamp supports; (27) a couple of platinum plates; (28) an air bath;
(29) a burette; (30) a pinch-cock, and (31) a brass scale with weights.
See Fig. 62.
All of the above apparatus can be bought of any dealer in chemical or
school apparatus for ten or twelve dollars. For advanced work you will
need other apparatus but whatever your requirements may be you can
either buy the apparatus ready made or have it made to order.
As to chemicals these will likewise depend on the nature of your
experiments. Send to Eimer and Amend, 205 Third avenue, New York
City, for a catalogue and price list of chemicals and chemical
apparatus as they sell everything used by chemists and electrochemists.
[Illustration: FIG. 62. SOME USEFUL CHEMICAL APPARATUS]
~Books.--~The following books with the exception of the last one are
good elementary treatises on chemistry:
1.--_Elementary Chemistry._ Smith.
2.--_First Principles of Chemistry._ Brownlee.
3.--_Chemistry._ Remsen.
4.--_Complete Chemistry._ Avery.
~How to Experiment with Electro-Chemistry.--~In working out
electro-chemical inventions you require a knowledge of both electricity
and chemistry for it is the electric current that produces the chemical
change either directly or indirectly.
[Illustration: FIG. 63A. AN ELECTRIC FURNACE, SHOWING THE DIFFERENT
PARTS]
An electric battery of any kind is electro-chemical in action and so
is _electroplating_ and _electrotyping_ but these are old inventions.
The production of _ozone_ and _nitric acid_ from the air by the action
of an electric spark; of coal tar colors by _electrolysis_; the
_electrolytic_ refining of copper and the electrolytic production of
aluminum are electro-chemical inventions in which the action of the
electric current is direct. And they are inventions of great importance
and of recent date.
[Illustration: FIG. 63B. AN ELECTRIC FURNACE IN OPERATION]
Then there are a large number of indirect electro-chemical processes in
which the electric current is used to produce heat as in the electric
furnace. Genuine diamonds, though too small and too costly to have any
commercial value, have been made in the electric furnace, shown in
Fig. 63. _Calcium carbide_ for making acetylene gas; _carborundum_,
an abrasive that is better than emery; _electric smelting_ and the
_reduction_ of _iron ore_ with carbon are all new electric furnace
inventions of great value, and there are many others.
BOOK.
_The Elements of Electro-Chemistry Treated Experimentally._ By Lüpke.