Chapter II: Part 2

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Watts, you know, are the measure of electrical power. They are the product of voltage (pressure) times amperes (rate of flow). Volts times Amps equals Watts. The nameplate on the appliance will give the voltage required for proper operation as well as either amperage or watts. If it gives wattage, you have the information you want. Otherwise you must multiply volts times amps to get the wattage. When voltage is given as 110-120, use 120 as your voltage. 120 volts is nominal today.

_How Much Will You Use?_

Now that you know the wattage of the appliance, multiply this figure by number of hours the equipment operates in one day. Divide this by 1000 to get the kwh. Now multiply the result by the number of days the appliance is used each month. This tells you the number of kwh used by the appliance during the month.

|---------------------------------------------|
| |
|Example No. 1 |
|_Yard Light:_ 300-watt lamp |
| |
|Amount of use: 3 hours per night. |
| |
|Multiply lamp wattage times hours of use |
|per night to get watt-hours per night. |
| |
|300 times 3 = 900 watt-hours per night. |
| |
|Divide watt-hours by 1000 to get kwh per |
|night. |
| |
|900 divided by 1000 = .9 kwh per night. |
| |
|Multiply kwh per night times 30 to get kwh |
|per month. |
| |
|.9 times 30 = 27 kwh per month. |
| |
|If the yard light is used 3 hours per night, |
|it consumes 27 kwh per month. |
|---------------------------------------------|

Example No. 2

_Coffee Maker_: 120 volts, 550 watts (from nameplate)

Amount of use: 1/2 hour per day.

Multiply wattage of coffee maker times hours of use per day to get watt-hours per day.

550 times 1/2 hour = 275 watt-hours per day.

Divide watt-hours by 1000 to get kwh per day.

275 divided by 1000 = .275 kwh per day.

Multiply kwh per day times 30 to get kwh per month.

.275 times 30 = 7.250 kwh per month.

If the coffee maker is used l/2 hour daily, it consumes 7.25 kwh per month.

_Calculate Operating Cost Per Month_

Now that you know the number of kilowatt hours an appliance uses, go to your rate schedule and your electric bill to see what the average kwh costs. Find the average cost of 1 kwh by dividing the amount of your bill by the total number of kwh used in a month.

_Example_: 410 kwh used. $14.35 total monthly bill

Average cost per kwh equals $14.35 divided by 410 kwh-3-1/2 cents per kwh.

Therefore, the cost of operating the coffee maker for a month would be 3-1/2 cents times 7.25 kwh--25.4 or 25 cents. Cost of operating the yard light would have been 94.5 or 95 cents a month.

(a) 6357 (b) 1963 (c) 8996

Correct answers to the meter readings shown on the preceding page.

Adding Low Cost Helpers

You can see, by looking at your rate schedule, that the average cost per kwh gets lower as you use more electricity. To find the cost of operating additional electrical equipment, the cost per kilowatt hour is found from the last "step" in the bill--the lowest cost per kwh of the electricity you're now using. Sometimes power suppliers give special rates for such equipment as electric water heaters.

WHAT TO DO: Find the Cost of Operating Electrical Equipment

Make and fill in the blanks of a chart showing the electrical equipment you have and the operating costs per month.

Make a chart for the home (refer to chart one). Show the probable operating cost of equipment you might add to what you now have.

Demonstrations You Can Give

Show how to read a meter, making one with plywood or cardboard. Dials can be painted on the main board. Arrows can be attached so they will revolve to give different readings.

Show how to find the wattage of various types of equipment.

Show how to figure the cost of the average kwh in a home.

For Further Information

Your leader can get additional material for you or you may want to have someone from your power supplier talk to your club, telling about meters, how they work and how they are regularly checked for accuracy.

Chart One-THE HOME

Column No. 1. 2. 3. 4.

Item Wattage Hours KWH per Cost per
Rating Used Month Month
per (col. 1x2)/ (Col. 3 x av. Remarks
Month 1000 kwh cost)

Electric Iron 1100 30 33 .80
Stove 880 60 52.8 1.21 (Special
rate)

LESSON NO. B-8 Credit Points 3

IRONING IS FUN WITH THE MODERN HAND IRON

When you are getting ready to go to school or to a party, it probably gives you a good feeling to put on a clean, freshly-ironed skirt, blouse or dress. But did you ever think about the electric iron that helps so much to give you that well-dressed feeling? When you were younger, you may have had a play iron and pretended to iron your doll's dresses. Now you are old enough to learn about real irons--the different kinds of irons, how the iron heats, the kind of cord needed, the type of outlet necessary, how to use safety rules when you iron, and even how to help with the ironing.

Important Things to Know

There are many different irons, but the two kinds most important for you to know about now are the regular dry iron and the combination steam-and-dry iron.

It isn't weight alone that makes an iron do its job, but the heat of the iron. The heat is given off in the sole plate. The automatic iron has what is called a _thermostatic_ control which holds the temperature of the iron at the heat you want. Some clothes need to be ironed with a very hot iron, while others need only to be pressed lightly with a cool iron. The thermostat keeps the iron at an even temperature after you set it for the heat you want. The thermostat is the heart of the iron.

Take a look at the iron used in your home. It isn't heavy to lift, and has a handle that fits your hand easily. It looks graceful and has a smooth bottom, called the sole plate. And it may have a narrow, pointed tip which is helpful in ironing pleats, corners and gathers.

The Iron and Safety

If you are going to learn to do some ironing yourself, the most important thing for you to remember is SAFETY. You should read all about the iron first in the instructions which came with it.

Never use an iron carelessly. Remember the safety rules:

1. An iron should never be left even for a few minutes without being disconnected. Turn off by removing the plug from the outlet, or by turning the control lever to "off."

2. Let the iron cool before putting it away.

3. Wrap the cord carefully around the iron after it is cold.

4. Always stand the iron where it will not fall off on a child or pet or your own toes.

WHAT TO DO: Learn About Your Iron

Materials Needed: An automatic iron, some old play clothes, towels, napkins or handkerchiefs, and an ironing board.

Steps to Take:

1. Watch an experienced person iron.

2. Ask questions about what clothes need to be sprinkled.

3. Study the thermostat settings on the dial or indicator.

4. Ask about the kind of fabric each piece of clothing is--cotton, linen, silk, nylon, etc.--and why the iron should be at high heat for some, cooler for others.

5. Set the thermostat for the amount of heat needed, and with an older person watching you, iron some handkerchiefs, napkins, bath towels, and a pair of play shorts or blue jeans.

6. During a month iron some of these articles for your family, keeping a record of how many you do and what they were.

7. Take care of your iron. Be responsible for storing it.

+--------+-----------------+-------------------+---------------------+
| | No. | | Store Iron Properly |
| Date | Articles Ironed | Type of Article | (check) |
+--------+-----------------+-------------------+---------------------+
| | | | |
+--------+-----------------+-------------------+---------------------+
| | | | |
+--------+-----------------+-------------------+---------------------+

IRONING IS FUN

1. I (use) (do not use) an adjustable ironing Board at home. If I do, I adjust it to the height that just clears my knees easily as I sit in a comfortable chair. Yes No

2. There are three kinds of irons usually used--dry iron, steam iron or a combination steam or dry iron. I use a ---- iron.

3. I (have) (do not have) the instruction book. (If you do, read about the iron.) I know the iron's parts by their correct names. They are----.

4. I disconnect the iron if I leave it even for only a minute. This is a safety measure as fires have been known to start from irons left connected. Yes No

5. I take hold of the plug--not the cord--when disconnecting the iron. Yes No

6. I wait until the iron is cold before wrapping the cord around the handle and storing the iron because----.

7. Most irons have a thermostatic control. The iron I am using has settings for----.

8. The purpose of the thermostat is----.

9. These fabrics need high temperature.----

These fabrics need medium temperature.----

These fabrics need low temperature.----

10. These fabrics need sprinkling.----

11. The heat and smoothness of the sole plate smoothes the wrinkles. Pushing down on the handle or moving the iron rapidly only makes ironing hard work. I will iron slowly and steadily arranging and moving the garment with the left hand while guiding the iron with the right hand. (Or the other way for the left handed.) Yes No

12. I have watched an experienced person iron. Yes No

13. I have practiced on handkerchiefs, napkins and pillow cases.

14. Here is my record of ironing for one month.

Month ----
Your Name ----

Date I have ironed:
---------+------------------------------------------------
|
|

Demonstrations You Can Give

1. Show a dry iron and a steam-and-dry iron. Tell the difference between them and when each is to be used.

2. Display garments that look nice because they have been ironed properly, and those that have been ironed improperly. Explain about the heat, thermostat, type of iron and why results differ.

For More Information

At a club meeting ask a parent to give a demonstration of ironing different articles. Some power suppliers or dealers have people who will demonstrate the proper way to iron, and how to care for irons.

LESSON NO. B-9 Credit Points 2

LET'S BE FRIENDS WITH ELECTRICITY

Plan a Hazard Hunt

Electricity can be your important lifelong friend and helper, so you will want to know all you can about it and how to treat it properly. However, careless and improper use of electricity can do a lot of harm. Used properly, and treated with respect, electricity can do wonderful things to help you every day in many ways.

For safe and proper use of electricity, all wiring, fittings, insulation, cords and plugs must be in good condition. You can be a detective and track down defects in any such type of electrical equipment that you may be using in your home or on your farm.

When you find anything that is wrong, and know where it is, and know what to do about it, you can very likely correct the condition yourself, such as replacing a worn extension cord with a new one. If you find defects in permanent wiring, or some places where wires are bare or terminals are needed, you should tell your parents about them.

SAFETY FIRST, remember, should always be on your mind when working with anything electrical.

WHAT TO DO:

_1. Have A Hazard Hunt_

Go on a Hazard Hunt to see how many electrical hazards you can find. Look for defects such as broken insulation, worn cords, splices that are not properly soldered and taped, loose connections, or switches that aren't working properly.

There are many ways to have a Hazard Hunt. Choose the method that will be the most fun. Use the Hazard Hunt Guide in this outline to check your home, and other buildings. Maybe you'll want to have a friend help check your home, then you help him check his. Or, why not give each member of your family a Hazard Hunt Guide and have a contest? Parents may want to team up against you and other younger members of your family to see which team can find the most electrical hazards in some set time--say 30 minutes.

Have a Hazard Hunt Committee in your club check all member's homes and buildings and report its findings at the next club meeting.

_To Make It More Fun_

1. Put a hazard tag, like the one shown, (Figure 1) by each hazard that is found. Leave it until the hazard is corrected. Have another contest to see which member of the family corrects the most hazards.

2. Report on your Hazard Hunt at the next club meeting. Tell about the Hazards found, and what you have done or plan to do about them.

3. Suggest that the entire club have an Electric Hazard Hunt at your club meeting places or any community building. This could be part of one meeting.

4. Have a contest between two teams in the club to see which team can get the most homes in your community checked by the Hazard Hunt Guide. Losers could give a party for the winners.

_2. Get Others Interested_

Promote a community Electric Hazard Hunt. Enlist the support of power suppliers, electric supply and equipment dealers, schools, newspapers, radio and television stations.

_What To Look For_

Make a complete tour of your home and other buildings and see how many hazards you can locate. When you find a hazard, put a tag near it to mark it.

SAFETY TIPS

Put hazard tags _near_ the hazard but _not_ directly on broken or frayed wires, insulators, fittings, or other wiring equipment. Do not touch them either. Badly-frayed wires should be disconnected immediately from the power supply. In this way, you will not expose yourself to shock by accidentally touching an exposed live wire that may be carrying current.

4-H Electric Hazard Hunt Guide

_Wiring and Protective Devices_

1. Cable or conduit splices not in boxes----

2. Cable or conduit not securely clamped in boxes----

3. Conduit or armored cable not properly grounded----

4. Cracked or broken insulators (Figure 2)----

5. Wire not completely covered with insulation----

6. Worn insulation on wire----

7. Old unused wiring not yet removed----

8. Outlets, junction and switch boxes not securely fastened and covers not in place----

9. Switches not working properly (sparks fly as switch is flipped) (Figure 3)----

10. Fuses not of proper ampere rating for circuit----

11. Extension cord used in place of permanent wiring----

12. Pull chain socket without an insulating link in the chain----

13. Pull chain socket near plumbing fixtures or where hands may be wet or one may stand in water----

14. No moisture-proof cords for outside weather conditions or heavy rubber cords for motors and motor driven appliances

_Lighting_

1. Fixtures in farm buildings installed so that they might be easily damaged

2. Lights in haymows and other dusty locations not protected by dustproof globes

3. Outside sockets not waterproof

4. Heat lamps not properly supported by non-current carrying wire, chains, or brackets (Figure 4)

5. Light bulbs not frosted, shaded, or placed so that light is diffused to prevent glare

_Auxiliary Wiring_

1. Outlets overloaded--in other words, "octopus wiring"

2. Extension cords placed under rugs

3. Extension cords run through doorways (Figure 5)

4. Extension cords or lamp cords should use underwriters' knot (Figure 6)

5. Plug connections fuzzy (Figure 7)

6. Extension cords run over heaters or radiators

7. Extension cords, or appliance or lamp cords, worn or frayed

8. Heating appliances without regular asbestos covered wire

9. Open sockets or outlets where a baby or small child might stick a finger or metal toy

10. Broken plugs (Figure 8)----

11. Loose prongs on appliance or lamps plugs----

How Many Hazards Did You Find?

Make a chart listing the hazards, their locations and what you did about them. Make your own chart and list what you find.

Demonstrations You Can Give

Show and tell others how to have a Hazard Hunt.

For Further Information

Check with your leader, then ask your power supplier or a local electrician to tell you about safe electrical wiring, connections and fixtures.

LESSON NO. B-10 Credit Points 3

HOW ELECTRIC BELLS WORK--FOR YOU

When was the last time you wanted to get a simple message like "You're wanted on the telephone," "There's someone here to see you," or "There's a car in the driveway," to someone around your place? Did you have to walk or run some distance and perhaps shout, too, to be heard by the other person? Perhaps you had to stop some other work, or interrupt your favorite kind of fun, to do this bit of messenger work.

If the nature of the message is like one of those mentioned, and the number of people in hearing is not too great, then perhaps you can use bells or buzzers or both to do some of your messenger work for you. Even though a bell or a buzzer can't talk, it can convey a message.

What to Do

1. Learn how bells and buzzers work, and learn about the many different kinds.

2. Plan and install a bell system for your home or farm.

Bells and Buzzers Can Tell a Lot

Electric bells and buzzers use the same basic principle as the telegraph system, invented by Samuel Morse in 1840. Although not as important today as it was before radio, telephone, and teletype became common, the telegraph is still in use.

Bells and buzzers, however, are very common and have many uses. They are most often seen in the form of doorbells, and rare is the new home that does not have one or more. Service stations have bell systems to let the operator know that a car is waiting at the gas pumps. A clock signal reminds the homemaker when the cooking time is completed. Children are called to and released from school classes by means of bells and buzzers.

Also, various alarms employing bells and buzzers warn us when it's time to get up, or even that the place is on fire, or that a burglar is trying to break in!

Let's find out how bells and buzzers work, what different kinds there are, the different ways you can control them, and how you can put them to work for you.

You'll find that buzzers and bells can help you with your 4-H projects, and with the proper controls, can be your eyes and voice in a dozen places at once.

Why They Buzz or Ring--Electromagnetism

If we were to look at an electric bell with the cover off, we'd find that it would be very much like Figure 1.

A push on the button, which is just a switch that is normally held "open" or off by means of a spring, sends the current from the battery or transformer through the circuit.

You will see that the current passes first through two small coils of wire, and each coil has at its center a piece of soft iron called the core. When the current is on, the core becomes magnetized and attracts another piece of iron called the armature with its clapper attached.

This action rings the bell, but it also breaks the current by pulling the spring away from the screw on its return to the power supply.

With the power off, the electromagnet lets the spring return the armature to its normal position, contact is made again, and the cycle starts all over again--just as long as you continue to push on the button.

Buzzers work exactly the same way, except that they do not have a bell and depend instead on the vibration of the armature for a noise that's not as loud or as musical.

Gongs or chimes, that strike only once when the button is pushed, are made by connecting the armature with the screw by means of a flexible wire.

A Special Kind of Electricity

Most buzzers and bells work on a much lower voltage than you normally find in the wires in your house. Some are made to work at 6 volts, others at 10 volts, and still others at slightly higher voltages.

You can get these low voltages by using one or more batteries, or by using a transformer connected to your house current. Most bells and buzzers are now powered through transformers.

How to Control Them

The push button is the most common means of control. You can use one button to control several bells, or several buttons to control one bell, or have several buttons control several bells. Because low voltage is used, adding extra buttons is simple, inexpensive, and safe.

Buzzers and bells can also be controlled by: _clocks_, as in the interval timer on an electric range or in a school class bell system; _temperature detectors_, as in a fire alarm or freezer alarm; _door and window trips_, as in a one-man repair shop or in a burglar alarm; and _treadles_, as in the driveway of a service station.

Pick the Right Bell or Buzzer

Some of the many different types of bells, and various ways of controlling them are suggested in the table below. Just remember that no matter what the job or conditions, you can probably find a bell or buzzer and controls that suit your need.

SOME TYPICAL JOBS FOR BELLS & BUZZERS

--------------------------------------------------------------------
Number and
Type of location Number and
bell or of bells Type of location
Job buzzer and buzzers control of controls
---------------------------------------------------------------------
Summon others In the house-- Enough to Push- One at the
to the small to cover all buttons telephone
telephone medium buzzers usual work and each
In locations extension
outbuildings-- phone
medium to
large bells
Outdoors--
large
weatherproof
bell
All transformer-
powered
---------------------------------------------------------------------
Notify club Medium to large One may be Hose One--in
member that bell-- enough--if diaphragm the
car is at his transformer- mounted on driveway
produce stand powered the back of -----------------------
the stand (Complete driveway
including control,
are available,
ready to plug in.)
--------------------------------------------------------------------
Warn of power Battery-powered One near Relay, One, at
failure to buzzer, medium the held open main
incubator or size poultryman's as long as switch of
brooder bedroom power is on, hatchery
closed by or
spring if brooder
interruption house
occurs
--------------------------------------------------------------------
Warn of Battery-powered One, in or Temperature One, with
dangerously buzzer, medium near the detector bulb
warm size kitchen (sensitive inside
temperature thermostat) freezer
in freezer
---------------------------------------------------------------------

How to Plan Your System

To save your time and steps when the telephone rings for someone else in your family who is some distance away, you can install a simple bell or buzzer system to summon that person.

First, you must plan what you are going to do. On a large sheet of paper, draw to scale (roughly) a plan of your house and grounds, including those places where phones are located. It will help if you rule off your paper in 1/8" or 1/4" squares and let each square equal one foot. Show the location of poles supporting your wiring.

Next, pick out those areas where you or others would likely be when someone else would answer the phone and want to call you to it.

After you have thought about this, and talked it over with members of your family, show locations on your plan where you think you would like to have buzzers or bells, and show a button beside each telephone. (Generally, you should have a bell or buzzer near each phone, also.)

Figure 3 shows diagrams of various types of systems, and will help you determine the number of wires you will have to install to connect the buttons and bells that you have planned.

Inside, you will connect your transformer and the various buttons and bells with ordinary indoor bell wire. Outdoors, however, you should use weatherproof 2-wire or 3-wire telephone twist.

Show on your plan the distances that must be traversed by each type of wire, and show the number of conductors in each. Don't overlook the vertical distances (one floor to another).

Materials You'll Need

Because no two situations are just alike, it will be necessary for you to make your own list of materials.

As a guide, however, here is a list of typical materials, with the quantities left blank, for you to fill in as your own requirements and measurements dictate.

10-volt transformer
--- Door buzzers
--- Doorbells
--- Weatherproof outdoor type bells
--- ft. indoor bell wire
--- ft. 2-wire weatherproof telephone twist
--- ft. 3-wire weatherproof telephone twist
--- lbs. staples (insulated)
--- entrance insulators (for attaching
weatherproof to buildings and poles)

Because your transformer must be wired into your regular house current, you should have some help on this from an electrician or other qualified person. Also, you should get that person to review your plans and materials list before you place an order.

Install According to Your Plan

With the aid of an electrician or other qualified person, install your transformer, and test it.

You may then go ahead and complete your signal system, checking carefully with your plan, and making sure that your installations are both electrically and mechanically secure.

Test your system in all possible ways that it might be used.

Demonstrations You Can Give

Build a demonstration board incorporating a farm or home layout, with pushbuttons or other controls and bells and buzzers appropriately located. Show and tell how the system would save time and energy.

Show and tell how some of these work, and their value: power-off alarm, freezer alarm, fire alarm, driveway alarm.

For More Information

Ask your power supplier or your nearest electrical supply house for catalogs or literature on various types of signal systems, or ask a dealer to show you equipment he has in stock.

LESSON NO. B-11

Credit Points 2

FIRST AID FOR ELECTRICAL INJURIES

What would you do if you saw someone who had been hurt by electricity?

Did you know that you could save his life, if you had taken the time to learn and practice a few simple rules of electrical first aid?

First aid training equips you to know what to do and what not to do for the injured until medical help can be obtained. While the main benefits are for you and your family, no one can call himself a good citizen if he fails to help a stranger who has been hurt.

The information given here is only for electrical injuries. Perhaps what you learn will inspire you to take a complete course in first aid.

What to Do

Learn how to prevent electrical accidents, and what to do if an electrical accident occurs.

1. Make an electrical hazard hunt in your home or on your farm. Point out to your parents everything that should be repaired or replaced for safety's sake.

2. Read the first aid suggestions that follow. Learn them.

3. Get to know the six steps that are outlined for mouth-to-mouth rescue breathing. Practice them on your brother, sister, or parents. Teach the entire family how to do it.

Electricity Can Kill

In this day of hundreds of uses of electricity, you should know about electrical dangers. Electrocution can occur from either low voltage (household type) or high voltage currents. Sometimes household voltages are more hazardous because people underestimate the dangers involved.

A fraction of an ampere passing through your heart muscles can be fatal. Your body offers some resistance to the flow of electricity to ground. If you are standing on wet ground or in water, or if your skin is damp, this resistance is greatly reduced.

Wire cables within walls and cords on appliances are all insulated with a shock proof covering. Continued use, age, or damage may expose a bare wire and create a hazard. The point of exposure need be only a fraction of an inch. Cords are often used and abused. Exposed wires and signs of wear are danger signals.

Always be wary of overhead wires. People have been injured or killed when kite strings, model plane control lines, irrigation pipe, and water well equipment have come in contact with the power supplier's or their own overhead wiring.

Prevent Accidents

Underwriters' Laboratories (UL) have taken steps to see that minimum safety standards are met in the manufacture of electrical equipment. Look for the UL label when you buy cords or appliances. Never place cords under carpets or furniture, or drape them over a nail. Replace or repair worn cords without delay.

Be especially careful when operating electric devices in the bathroom. Keep in mind the dangers of a wet floor, grounded metal pipes, and wet skin. Turning on an AC radio while you are taking a bath is asking for real trouble.

There may be shorts in electric devices. Keep your hands dry when using them, and do not touch them along with grounded metal objects. If you ever get a slight shock, sound the danger signal and do something about it.

Think, Then Act

Your first thought in rescuing a victim from an electrical accident should be your own safety. Speed is also important, because a few seconds or minutes may save a life.

The first question you should ask yourself is "Can I quickly turn off the power?" This would be easier to do in the home than outside. In the case of a victim trapped in a bathtub from a radio accidentally knocked into the water, it might mean simply removing the plug from the wall outlet. If a victim is found grasping shorted, permanently installed equipment and cannot let go, the main switch might be used for quick release of the current.

Outdoors, especially with high tension wires, your danger in rescue is much greater. To handle the victim, touch him only with a long dry stick, dry rope, or a long length of dry cloth. Be sure your hands are dry and that you are standing on a dry board. A broom might be a good lever to pry a victim from a high tension wire but never use a green stick containing sap.

First Aid

Once the rescue has been made and the victim is free of further danger, check to see if breathing has stopped. If so, start artificial respiration _immediately_ and send someone for a doctor.

Artificial respiration must be started as soon as possible after normal breathing ceases. _Most persons will die within 6 minutes or less if breathing stops completely unless they are given artificial respiration._ Precious minutes may have passed before you get to the victim. Since the victim may be within seconds of death by the time you are able to touch his body, you should seek to obtain an air flow to and from the lungs _immediately_.

The victim may seem stiff as an effect of the current, so don't give up easily. Continue the procedure for several hours. If transportation is necessary, remember that there may be internal injury, fractures, or severe burns.

Mouth-To-Mouth Rescue Breathing

There are various effective ways to give artificial respiration, each with its advantages and disadvantages. The mouth-to-mouth method is recommended as a good one to master. It can be used on victims of drowning, suffocation, and asphyxiation, too. People have been known to save lives with less exposure to the correct procedure than you are getting by reading this. So, pay attention and remember what you read.

Step 1. Turn the victim on his back. Wipe out victim's mouth quickly. Turn his head to the side. Use your fingers to get rid of mucus, food, sand, and other matter.

Step 2. Straighten victim's head and tilt back so that chin points up. Push or pull his jaw up into jutting out position to keep his tongue from blocking air passage. This position is essential for keeping the air passage open throughout the procedure.

Step 3. Take a deep breath, place your mouth tightly over victim's mouth, and pinch nostrils closed to prevent air leakage. For a baby, cover both nose and mouth tightly with your mouth. (Breathing through handkerchief or cloth placed over victim's mouth or nose will not greatly affect the exchange of air.)

Step 4. Breathe into victim's mouth or nose until you see his chest rise. (Air may be blown through victim's teeth, even though they may be clenched.)

Step 5. Remove your mouth and listen for the sound of returning air. If there is no air exchange, recheck jaw and head position. If you still do not get air exchange, turn victim on side and slap him on back between shoulder blades to dislodge matter that may be in throat. Again, wipe his mouth to remove foreign matter.

Step 6. Repeat breathing, removing mouth each time to allow air to escape. For an adult, breathe about 12 times per minute. For a child, take relatively shallow breaths, about 20 per minute. Continue until victim breathes for himself.

What Did You Learn? True or False

1. A broken arm should be splinted before artificial respiration is applied to a victim who is not breathing.

2. A person who has been severely shocked with an electric current should lie down.

3. A doctor should be called even though you successfully have revived a victim's breathing.

4. A fraction of an ampere through the human heart muscles can be fatal.

5. A copper wire would provide a better path than your body for stray currents, therefore all appliances should be grounded if possible.

6. Outside wires are never a hazard because they are covered with insulation when they are installed.

7. Cords need not be repaired until you can see bare wires.

8. Tuning in an AC radio while you are bathing is always dangerous, even though your hands are dry.

9. In an emergency, a broom is an acceptable tool for prying a victim off a high tension wire.

10. In mouth-to-mouth breathing, an adult's lungs should be filled 12 times per minute and a child's 20.

Demonstrations You Can Give

Show how to deal with an electrical first aid "problem" given to you by your leader.

For More Information

Ask your leader to have a first aid expert put on a demonstration. (Many industrial plants and power suppliers have such people.)

LESSON NO. B-12

Credit Points 3

HOW ELECTRICITY HEATS

In ancient times, people thought that heat was a material just as air is. They called it "caloric". When something got warm, they said, caloric flowed into it. When something cooled off, caloric flowed out of it. It did not bother them that they could not see caloric. They could not see air either!

Now we know that heat is not a material. It does not take up space. It does not weigh anything. Instead, it is a form of energy. And when we say that heat is a form of energy, we mean that it can be used to do work.

What to Do

1. Make a simple resistance heater.

2. Make some popcorn by:

(a) conduction (b) convection (c) radiation

"Resistance" Makes Heat

There are at least four ways that electricity can make heat. The one that we'll cover here is _resistance_ heating. (The others are: _dielectric_ heating, where the lines of force of an electrostatic field pass through a non-conductive material and heat it; the _heat pump_, which is a refrigerator in reverse; and _electronic_ heating, which uses high frequency waves similar to radio waves to create high speed movement of the molecules or tiny particles which rub together to make heat.)

_Resistance_ heating occurs because every conductor of electricity opposes the flow of current through it. Some conductors resist more than others. When they do, a certain amount of warming takes place. The more resistance that is offered, the more heating there is.

Some materials, like silver, copper, and aluminum, offer little resistance. We say they are good conductors.

Other materials, like iron, offer more resistance. They are still conductors, but not as good as the others mentioned.

The _size_ of the conductor, and its _length_ are the other two things that affect its resistance. The _smaller_ it is, the greater its resistance. Also, the _longer_ it is, the greater its resistance. Therefore, when we only want to _move_ electricity from place to place, we want relatively large, "good" conductors. Here, we do not want to make heat. In fact, we want to avoid it, because too much heat in the wrong place can cause a fire.

But when we want heat, we choose relatively small, "poor" conductors, and the more heat we want, the longer they must be. If you will think of the filament inside a lamp bulb; you may recall that it is a very fine wire, coiled so as to get a maximum length, and made of tungsten which has a high resistance.

Because of all these factors, this filament glows at a white heat, and is a source of both light and heat.

Make a Simple Resistance Heater

_Materials you will need_:

1 dry cell battery
1 foot iron picture wire
Pliers

Use a short strand of iron picture wire and hook the ends to the terminals of a dry cell battery. Use pliers so that you do not burn your fingers. Disconnect the wires as soon as they become hot. Tell why the wires heat.

Conduction is "Touching" Heat

Conduction occurs when you set a pan containing food right on a heating element. An egg cooking in a hot frying pan is a good example of conduction at work. This method is the most efficient single way of using electric heat for cooking.

Convection Depends on Air

Convection warms food in pans that are not actually touching the heating element. It uses the hot air around the element to carry heat to the pan.

Your oven in your range works by convection. Most houses are warmed in winter in the same way. The heat produced in a furnace warms the air as it circulates through. This air in turn keeps your body warm.

Radiation is Like the Sun

Radiation heating is more difficult to explain. It results when heat or energy waves strike an object and are converted into heat. The energy we receive from the sun is a good example. When you are wearing dark clothes on a chilly day, you may become uncomfortably hot. The sunshine warms you even though the air around you has not been heated. Radiant energy has a way of being absorbed by dark objects and reflected by light colored or shiny surfaces. Did you ever notice how snow melts faster on a black top road than it does on a concrete road?

The electric heat lamp is one of the most familiar sources of radiant heat. Other examples are panels and cables that are built into the walls and ceilings of homes to provide heat.

Make Popcorn 3 Ways

How do you make popcorn? Did you know that you can do this kind of a heating job three different ways?

_Materials Needed_

Popcorn
Cooking oil or shortening
Salt and butter
4-qt. saucepan, with cover. (A glass cover
is preferred.)
Potholder
Electric range
2 250-watt heatlamps
2 spring clamp type lampholders
Wire mesh corn popping basket or wire
mesh kitchen strainer (improvise a
screen wire cover)

_First_, make popcorn the way you usually do. Set a front surface unit control on the range at "medium high". Pour enough oil to very lightly cover the bottom of the pan. When the pan is hot, pour in enough popcorn to cover the bottom with one layer of kernels. Use the potholder in one hand to hold the cover on, and with the other move the pan back and forth across the unit. When the popping stops, remove from the heat.

How did the heat get to the popcorn?

_Second_, make popcorn in the oven. Add the oil to the pan, cover it and put it in the oven. Turn the oven on, with the automatic control set at 400 deg. When the oven indicator light goes off, this means that the proper temperature has been reached. With the potholder, remove the pan and add one layer of popcorn kernels. Replace the pan in the oven. When the popping stops (listen for it) remove the pan.

What kind of heating took place here?

_Third_, make popcorn with the heat lamps. Clamp the lampholders to the back of a chair or other vertical support. They should be 6 to 8 inches apart and pointed directly at each other. Put about 2 tablespoonfuls of popcorn in the Wire basket or strainer. Do not add oil. Hold the basket midway between the two lamps. When the popping stops, turn off the lamps.

What kind of heating was this?

Now, butter and salt the popcorn you have made and share it with others.

What Did You Learn?

1. How is heat transferred from one body to another?

2. Could chicks or pigs receive warmth from a heat lamp without the air in the pens becoming warm? Explain.

3. How does a broiler unit in a range cook meat?

4. How does an oven bake food?

5. Tell why iron picture wire was used instead of copper wire for your heating demonstration.

LESSON NO. B-13

Credit Points 2

MYSTERIOUS MAGNETISM

In ancient times, people found certain rocks that clung together in bunches. These rocks were very mysterious. People didn't understand them and many superstitions grew up about lodestones, as these rocks were called. Lodestone (sometimes spelled loadstone) means leading stone. People even told Columbus not to sail out of sight of land because a giant lodestone was just over the horizon waiting to pull all the nails out of his ships.

The Chinese were the first to use magnets. They found that if you hung a lodestone by a string, one end of the stone would always point in the direction of the North Star. They had the first magnetic compasses.

An artificial magnet can be made by stroking or gently rubbing a piece of steel with a lodestone. This piece of steel then can be used to magnetize another piece of steel. This can be continued on and on. Lodestones are not always available but you can get the same results with an electric current. So, magnetism and electricity are very closely related.

What to Do

Learn about magnetism by doing the experiments that follow.

Seeing is believing!

Materials You Will Need

2 dry cell batteries (#905)
A few feet of No. 18 bell wire
3 steel knitting needles or similar hard steel
2 ft. of light thread
Sheet of light cardboard or stiff paper
Permanent magnet (bar or horseshoe)
Compass
1 or more large nails or spikes
Red and black china-marking pencils or crayons

Iron filings
Wire cutters
Carpet tacks

(Iron filings usually can be found under the grinding wheel in a shop. If you can't find any, rub some steel wool pads together to produce bits of metal that will do.)

"See" a Magnetic Field

Cover the permanent magnet with the cardboard or paper. Sprinkle iron filings on the paper. Tap the paper and note the pattern formed. Strings or lines of filings pass from one pole of the magnet to the other. The area covered by the filings is the center of the magnetic field. To remember this, you might compare the magnetic lines of force that arrange the iron filings to the contour strips in a farmer's field.

This magnetic field is one of the important things in our everyday life with electricity. If it were not for the magnetic field, we would not have electric motors. Telephones, radios, television, and many other things we use every day also depend on this magnetic field.

Make an Electro-Magnet

You can make magnetism work for you by winding several turns of insulated wire around one or more large nails or spikes (soft iron). Connect one end of the wire to the battery. Touch the other end of the wire to the other terminal for a few seconds and see how many tacks you can pick up. Repeat the experiment using as many turns as possible. How many more tacks were you able to pick up?

You have made what we call an electromagnet. When you disconnect the wire, the nails fall off. This is one of the advantages of an electromagnet. We can turn magnetism on and off as we wish. Picture a crane operator throwing the switch and picking up scrap iron and steel. Then he opens the switch to drop the scrap metals.

Soft iron can be magnetized easily as you have just seen, but loses its magnetism in a short time. Steel is harder to magnetize but holds its magnetism almost indefinitely.

Make a Permanent Magnet

Wrap the insulated bell wire around the steel knitting needle. The wire should be wrapped the full length of the needle. One end of the wire is connected to the battery. The other end of the wire is then touched for just a few seconds to the other terminal. This should make the needle into a permanent bar magnet. If you did not get results, try two batteries in series, wind more turns of wire on the needle, and leave it connected a little longer. Do the same thing with the second knitting needle. In the same way, you can magnetize a screwdriver, so that you can use it to pick up and hold steel screws. Don't do it unless you want your screwdriver to be magnetized.

See How They Attract and Repel

Take one of the magnetized needles and hang it with a thread. A thread stirrup (Figure 4) will help keep it level. Be sure it is not near other large pieces of steel. Watch the needle. Does it settle down, pointing in one direction? (Check to see if this is the same direction as your compass). If it does, you have made a compass. The tip of the needle pointing north is called the North Pole (North-seeking pole). The other end is called the South Pole. Mark the North Pole with a stroke of the red marking pencil. Mark the South Pole black. Do the same thing with the second needle. You can show this with a sewing needle, and a notched cork, and a bowl of water. Rest the needle in the notched cork, and float it on the water.

Hold the compass near the North Pole of the needle. What happens? Does the South Pole of the needle attract the North or South Pole of the compass? Try this with the second magnetized needle. See if you can prove the rule that like poles repel (drive away) and unlike poles attract.

Connect one end of a wire loop to the battery and run the wire directly over the compass. Touch the other end of the wire to the battery. Which way does the compass point now? If you get some motion out of the compass needle, this proves there is a magnetic field around the wire when current is flowing. This relation between electricity and magnetism is the thing that makes electric motors and generators work.

Make Many From One

Lay the third needle (unmagnetized) on a table and stroke it with one of the magnetized needles. (See diagram) Always stroke it in the same direction. Raise the magnetized needle at least two inches on each return stroke. Thus you can magnetize the needle by using the other needle.

Use the wire cutters to cut the first magnetized needle in short lengths. (Cover the needle with a cloth to keep the pieces from flying.) Can you show by using the compass that each piece is a complete magnet? Hold one end, then the other, of each piece to a compass. Does each piece have both a North Pole and a South Pole?

Magnetism and Animals

The things you have done show that electricity and magnetism are related in many ways. Magnetism is mysterious, and there are still things to discover about it. It is thought that animals and birds are aided in their sense of direction by magnetism. It is commonly known that when a person gets lost in the woods, he tends to go around in circles. Possibly this is caused by the earth's magnetic field.

What Did You Learn?

1. Where are natural magnets obtained?

2. How can artificial magnets be made?

3. What material is needed for a permanent magnet? For a temporary magnet?

4. How can you find out which is the North Pole of an unmarked magnet?

5. How many poles does a magnet have?

6. Which magnetic poles attract each other?

7. Why couldn't you make a compass out of a strip of plastic?

8. What causes the compass to change direction when a wire carrying battery current is held over the needle?

9. List the materials you would need and tell how you would build a homemade compass.

10. Tell what you enjoyed most about becoming acquainted with mysterious magnetism.

LESSON NO. B-14

Credit Points 2

Give your appliances and lights a square meal

Would you say that having enough to eat was pretty important in the home that you know?

The "food" for your appliances and lights is electricity, and like you they must be "fed" enough.

What to Do

1. List the appliances and lights in your home.

2. See if any of them are "starving" for the electricity they need.

3. Learn how the electricity gets to where it's used.

4. Make a chart of the electrical circuits in your home.

5. Make sure that each circuit is protected with the right fuse or circuit breaker.

Count Your Electrical Blessings

Many people in much of the rest of the world wish that they could trade places with us, because we have so many electrical appliances in our homes.

Of course, we have not always had as many appliances as there are today. When electricity first came along, people used it only for lights. Then, they began to add flatirons, washing machines, refrigerators, coffee percolators, and radios.

Then more and more electrical things were made for people to use and enjoy. Now we have dozens and dozens of uses for electricity in our homes.

How many different uses for electricity are there in your home today? Ask your parents how many there were when your home was built or first wired. How many were _common_ when your parents began to keep house?

Some Homes Are Behind Times

Many older homes were built before electricity was available, and were wired later. And like them, some older homes that were wired as they were built had only enough wiring for lights and a few other appliances, because those were the only uses that were known at that time.

But people kept on living in these homes, and kept adding to the uses they made of electricity without adding to their wiring.

What has this meant? Well, if electricity were like cars and trucks, you could say that some people are trying to put turnpike traffic through a back-country dirt road!

Watch for Signs of Starvation

Of course, as your state has done with its highways, some people have expanded and modernized their wiring. But many others have not yet seen this need, or if they have, they may have to do it again.

Here's why:

Your power supplier delivers current to you at the right voltage or electrical pressure. If the wires in your house are large enough, they will pass this full voltage on to the appliances.

But if your wiring is too small, the electricity arrives at the appliances so weak that they can't work properly, and much of what you pay for is wasted.

Here are some things you can watch for in your own home. They will tell you whether your appliances are getting enough electrical "food" or not.

1. _A shrinking TV picture_--If it draws in from the sides of the screen, fades, loses contrast, or if the sound becomes distorted, you may have low voltage.

2. _Too much fuse blowing or circuit breaker tripping._

3. _Heating appliances are slow to do their jobs._

4. _Lights dimming_, when motors or other appliances are turned on.

There Should Be Enough Ways to Get "Appliance-Food" Around

If appliances in your home show these starvation signs, then you may not have enough ways for the electricity to get to where it's used.

There are three kinds of these electrical highways or circuits, and your home should have enough of each:

1. _General purpose circuits_--These serve lights all over the house, and convenience outlets everywhere except in the kitchen, laundry, and dining areas.

A rule-of-thumb is: There should be at least one general purpose circuit for each 500 sq. ft. of floor space.

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Electricity for the 4-H ScientistChapter II: Part 2

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