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The Mariner's Compass

What is a magnet? What are the poles of a magnet?

What is a temporary magnet? - What is a magnetic field ?
Is the earth a magnet? — How find the earth's magnetic
poles ? — Exercises and summary.

How Man Uses Electricity

What is an electromagnet ? How do we ring an electric

bell? — How can a telegraph wire carry a message ?

How can
a current silverplate a spoon? How does electricity produce
heat and light? – How does a dynamo produce a current? .
How does electricity produce motion ?- Exercises and summary.

The Light of Day

Why can we see objects ? How does sunlight travel ?

How does a mirror change light? - Why does an object have
a shadow? — How does distance affect the brightness of light? -

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Light in the House

How do we get sunlight into the house? How have men

lighted their houses at night? - How do kerosene lamps work?

How do we get light from gas? — How does a fuse box pro-
tect a house? How are gas and electricity measured ? How
are gas and electric meters read ? - What is the right way to use
light? — What is indirect lighting? — Exercises and summary.

The Sounds We Hear

What causes a sound? How do we hear? What causes

an echo?

What is the difference between noise and tone?
What are the classes of musical instruments? — How does a
telephone carry sound ? — Exercises and summary.

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Man's Simple Machines

How does man lighten his work ? What advantage do we

get from machines ? - - Is a teeter a machine ?

How many ma-
chines do we use? — How does a lever help us? How do
pulleys help us ? How do we use a wheel and axle ? Of what
use are the wedge and the screw? — Why do we oil a machine?
Exercises and summary.

Man's Great Machines

How does a sailboat use the wind? — Why do kites fly?

Why do airplanes rise? . Why do windmills turn? How has
man harnessed water? How does the sewing machine lighten

work? How is cream separated from milk? - How does a
vacuum cleaner work? — How can we wash clothing by elec-
tricity ? How do gases cause motion ? - How does an engine
run? — What makes an automobile run? — Exercises and sum-
mary.

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The World of Plants

How do plants live? What parts has a plant? How do

seeds begin growing ? · What are leaves like?

What are
leaves made of ? What is the work of leaves ? – How does a
plant climb ? What are stems and buds for? What is the
work of roots ? — Why do plants have flowers ? — How are seeds
formed and scattered ? - What are the lower plants like?
Are wild flowers worth preserving ? — Exercises and summary.

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Plants of Use to Man

How does man make use of plants ? - Loes man eat grass?

What grasses do we use? How do corn and rice grow?
How do sugar cane and bamboo grow? — Why is wheat flour
used for yeast bread? — What are the legumes ? — How do
legumes capture nitrogen ? — Why do we eat vegetables ?
What fabrics do we get from plants ? What is a fruit?
Exercises and summary.

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Our Plant Friends and Foes

How are trees our friends? How does a tree get its shape?

What is the inside of a tree like? What are sapwood and
heartwood ? - How are trees cut into lumber? — What are
the uses of wood ? - How is paper made? What are the

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Animals of Importance to Man

How many kinds of animals are there? Have animals

helped, or hindered, man's progress ? - What are man's beasts
of burden? What animals give us meat? Why is milk valu-
able? What is leather? — What birds give us food? — Why
and how should we protect birds? — What fishes are used by
man? What are insects like? — What insects give us food ?
What are our insect enemies? — How may flies and mosquitoes
be destroyed ? - Exercises and summary.

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How Food is Digested

What organs digest our food ? - How does the mouth help

in digestion? What is the work of teeth? - How do we
swallow? What is the structure of the stomach ? — What
happens to food in the stomach ? — What are the intestines
like? What happens to food in the intestines ? — What
should our diet be? – Is alcohol a food ? -- Exercises and sum-
mary.

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