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Copyright 1953 by Ducnewald Printing Corporation.
Lithographed in the United States of America.
MACHINES AT WORK
By Mary Elfing
GARDEN CITY BOOKS GARDEN CITY, NY
You could do everything that the machines
in this book do. For some of the jobs, of course,
you d have to get friends to help you. But people
have always been able to work and build wonderful
things, using just their muscles. And they can do a very
great deal more when they use their brains, too. They
can invent machines to make work thousands of times
easier and faster.
The big machine in the picture is a shovel that's
used for digging an enormous hole. In one bite, its
scoop can tear out a chunk of earth more than twice
as tall as a man. Its long arm, called the boom, lifts the
load as high as the top of a seven story building, then
swings around and drops it almost a city block away.
There are only a few shovels like this in the world.
They were especially made to work where beds of coal
lie close to the surface of the earth, covered by a layer
of soil. The shovels clear away the soil so that other
machines can dig out the coal.
When a giant shovel has cleared off one spot, its
crawlers begin to turn, and it creeps slowly ahead. But
it can't travel on roads. It's far too big and heavy and
tall — so big, in fact, that it came to the mine in sepa-
rate pieces. Forty-five freight cars were needed to haul
all the parts for just one machine from the factory to
the mine. Then experts put the parts together right
where the shovel was to start digging.
And dig it does. In one minute its scoop can bite
out as much dirt as 3,600 men could dig just using
their muscles to lift ordinary hand shovels!
The giant shovel is one of the biggest machines
ever made, but there's another that can lift even bulkier
things. It is an overhead crane that works in a shipyard.
Often the crane hoists big boilers out of ships so
that repair men can work on them. It is so huge that
it carries another crane on its back. The piggy-back
crane — that's its real name — reaches down and lifts
things off the deck of the ship, too.
Hammering is another kind of muscle work that
machines can do quickly and easily. Suppose the water
pipes under your street need mending. Repair men
have to tear up the pavement in order to reach the
pipes. So they bring in jack hammers to do the pound-
ing. Strong blasts of air run the hammers, and, in no
time, the pavement is broken up.
Crushed rock was used for making the paved street
in the first place. It came from a big machine called a
rock crusher, which breaks up chunks of stone into
small pieces. Strong jaws inside the crusher chew
at the stone until they have made it into bits that are
just the right size.
An even bigger
pounding machine is
the pile driver. It can
hammer a great thick
log down into the
ground almost as easily
as a man can hammer a
nail through a board.
One kind of pile driver
does its pounding job
with a steam piston.
Another kind lifts a
heavy weight and lets
it bang down on top of
the log, called a pile.
The one in the picture
works in a harbor. It drives piles deep into the earth
that lies under water. A whole group of piles make
the foundation for a pier in the harbor, for ships to
tie up alongside.
Harbors and rivers must be kept safe for ships. If
mud and sand pile up in a thick layer on the bottom,
ships may get stuck. So dredges go to work clearing the
mud and sand away. Often a clean-up job takes a long
time. The men who run the machinery live on board
the dredge, just as sailors live on a ship.
Some dredges have scoops that dig under water.
Others, like the one in the picture, use giant suction
pumps. The mud or sand they suck up is called spoil.
If there's hard-caked mud on the bottom, cutter
heads break it up. Then it's ready to be pumped out
through huge steel pipes that stretch away from the
dredge like a great snake and pour the spoil out on land.
Of course, a dredge must stay in one place while
it is working. So it carries along two huge spikes called
spuds. These move straight up and down at the stern
of the dredge. When they ram into the earth under-
water, they keep the dredge from drifting.
A spud is so heavy that it pokes its own hole in the
muddy bottom of a river or harbor. But making holes
on dry land is a different problem. For instance, you
can't just poke a telephone pole into the hard ground.
or pound it in easily with a pile
driver, either. So, in many
places, a machine bores holes
for telephone poles, just the
way a carpenter bores a hole
with a brace and bit. Then the
machine's long arms reach out,
lift a pole into the air and plug
it down neatly into place.
Long ago our ancestors dis-
covered how to use simple tools
— such as hammers, shovels,
crowbars and rollers. These
things seem very ordinary to us,
but they were really wonderful
discoveries. The clever men
who invented them were pro-
viding ideas, one by one, which
scientists and engineers used
much later. Our great machines
are combinations of many,
many things that men discov-
ered from using simple tools.
The giant shovel digs; the overhead crane lifts; the
pile driver pounds. All machines multiply the power
that's in the muscles of men — or of animals. The
pushingest animal is an elephant. In some places in the
world, elephants are trained to clear land by putting
their foreheads against a tree and heaving until the tree
A tree-dozer can out-push an elephant. The one in
the picture has a special forehead built in front. With
a slow, steady shove, it clears the way for roads or
opens up fields for farms.
Farmers used to dig their fields by hand. Then they
hitched horses to plows. Now a tractor does the work,
but we still measure its strength in horsepower.
MACHINES FOR FARMERS
Dan is a farmer. He knows how to use almost any
kind of farm machine, and he has lots of them. The
most important is his tractor, for it is busy all year
round. Sometimes it pushes. Sometimes it pulls. Or it
may stand still and lend its power to other machinery.
When the frost is out of the soil in the spring, Dan
backs his tractor into the tool shed and bolts on a plow.
This one is a two-gang plow — it can make two fur-
rows in the earth at the same time. Dan touches a lever.
The blades of the plow lift up so they can't dig into the
farmyard and the road, and Dan chugs off to the field.
Another touch on the lever sends the blades down. In
a few minutes, Dan has made the first furrows across
Now he has to turn. He lifts the plow and steps on
the left brake pedal. While the big left wheel stands
still, the right one keeps going and turns the tractor,
ready to start the next furrows. When Dan wants to
stop, he steps on both the left and right brake pedals
After plowing comes harrowing. The tractor pulls
a different implement for this job — a whole row of
saucer-shaped metal discs that chew up the soil and
spread it out evenly. Now Dan is ready to plant corn.
The corn planter does five jobs in one trip down
the field. It makes trenches for two rows of corn. It
drops corn seeds into the trenches. It drops fertilizer
alongside to give food to the young plants. It covers
the seeds. And it leaves a mark all along the field to
show exactly where the tractor should go to plant the
next row of seeds. Dan follows the mark very carefully.
All the rows must be exactly the same distance apart,
because the tractor will have to go through the field
again to cut out the weeds after the corn starts to grow.
If the rows are badly spaced, the tractor wheels will
squash some of the plants.
when Dan was a little boy, he used to help his
father hoe the corn by hand, getting rid of weeds and
loosening the soil. Now he has an implement called a
cultivator which does the job.
After the corn is well up, Dan pulls the cultivator
through the field, driving carefully, with the wheels
between the rows. Small blades on the cultivator cut
through the weeds and break the soil into loose chunks.
The pictures show several kinds of cultivator blades.
All summer long the corn grows tall. Dan waits till
the ears are dry before he harvests them, ready for his
cows and chickens to eat in winter.
Dan's farm is small, so he can't afford to buy a big
corn-picking machine. But his neighbor Al has one that
he rents out, and one morning Dan drives it to his
cornfield. His tractor seems lost inside the picking
machine. Gatherers that look like the pointed snouts of
huge mice creep along in front of the tractor close to
the ground. One by one the stalks of corn go into the
machine, which snaps the ears off. Then revolving claws
and rubber paddles rip off the husks, and an elevator
carries the clean ears back to a wagon which the tractor
pulls along. In a very short time, Dan's whole field is
Corn isn't the only thing that grows on Dan's farm.
He raises tomatoes for the market, too. At planting
time, he needs two helpers who ride on little seats very
close to the ground behind the tractor. They put the
tender little tomato plants one by one into a trench
which the planting machine digs, and then a special
wheel covers the roots with earth.
Dan has some wheat fields, too. In the spring, after
the ground is harrowed, a wide planting machine sows
many rows of wheat at a time. And it drops out ferti-
lizer to feed the plants on the same trip.
Many farmers use their tractors for harvesting
wheat, but Dan doesn't. Instead, he rents a shiny red
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reaper which he calls a "package job," because it moves
itself along and does the whole harvesting at once. It
cuts the wheat, shakes the grain loose from the stalk
and separates it from the husks. If there are weeds grow-
ing in the wheat, the machine separates the weed seeds
from the wheat kernels and spills them into different
Dan sits high in the air at the front of the machine.
He says he has a ''box seat.'' Behind him on a bench sits
a helper who ties the bags as they fill up and puts new
bags in place. Dan says it won't be long before some-
body invents a machine that will reap the wheat, grind
the flour and bake bread right there in the field!
All of Dan's machines are wonderful inventions, but
they can be dangerous, too, if people are careless. To
give himself and his helpers warning, he has painted
bright stripes and markers around open places where
fingers might get caught in moving parts.
Dan has a flock of fine white Leghorn chickens. He
takes care of them by machinery, for eggs are a crop,
too. The hens live in cages with wire floors, so that they
keep very clean. All their droppings go through the
wire to a platform below. With a special scoop, run by
his tractor, Dan cleans the manure from the platform
and puts it in a pile to be used as fertilizer on the fields.
Every day the chickens have their meals brought to
them on a moving belt. The eggs they lay drop through
their nests onto another belt that carries them away.
Finally a machine sorts the eggs according to size, ready
Some farmers raise chickens for the market. Of
course, the feathers must be taken off after the chickens
have been killed. There are machines for this, too. One
kind has mechanical fingers that pluck the feathers as
chickens go past on a moving belt.
MACHINES FOR BIGGER FARMS
Dan's neighbor Al has a big dairy farm, with lots of
cows to milk every day, and land enough to grow their
feed. Besides his corn picker, Al has other special ma-
chines. One of them cuts corn while it is still green,
chops it up fine and loads it into a truck. The truck has
a sort of cage over it to keep the corn from spilling out.
Next, Al turns his tractor into a stationary engine which
runs a blowing machine. A wide belt from a pulley on
the tractor turns the blower, which shoots the chopped-
up corn to the top of a storage tower called a silo. The
green stuff ferments in the silo and turns into wonder-
ful food for the cows.
AFs fields are so big that he needs larger plows than
the one Dan uses. He hires an airplane to spread dust
that kills plant-eating insects.
Al plants his hayfields with a seeding machine that
he pulls behind the tractor. Grass seed is so tiny that it
can't be planted deep. Al's seeder sprinkles just the right
amount of seed on the soil, and then squeezes a thin
covering of earth on top. He says the machine "tucks
each seed to bed.''
After the mowing machine has cut the hay, Al pulls
his automatic baler across the field. The baler scoops
the hay up, then presses it into a box-shaped bundle,
slices it off neat and square, and ties it
with strong twine. One by one the
bales drop out on the field, ready for
a truck to pick them up.
Some farmers rake their hay into
long heaps called windrows before they
bale it. The machine that does this job
has many teeth that whirl round and
push the hay sidewise into the wind-
rows. The whole field has a rolling look,
like ocean waves.
The hay must be dry before it goes
into the barn. If it isn't, it may get
moldy. And green hay may even be
dangerous. It can actually make heat
enough to start a fire.
To be sure his hay keeps well, Al
has a blower that circulates air around the barn and
dries the bales completely.
Some farmers use machines that tie the hay into
round bales. Others don't bale it at all. They use stack-
ers to pile it into tall stacks where it is kept till the cows
are ready to eat it.
The stacker fits onto the tractor. When it was first
invented, farmers thought it was a sort of luxury, be-
cause it was used so seldom. Then they discovered that
they could put it to work on other jobs, too. If a plat-
form of boards is fitted across the forks of the stacker,
it turns into an elevator that a man can stand on. Then
he can paint the barn or pick apples from high branches
without having to climb up and down ladders.
It would take a lot of work to milk all of Al's cows.
So he uses milking machines. When a man milks a cow,
he squeezes with his fingers. Instead of fingers, the milk-
ing machine has four soft rubber funnels that fit over
the cow's teats. A pump squeezes the funnels, presses
the milk out and sends it through hoses to the milk can.
A farmer has only two hands. His milking machine
has four funnels with hoses. So it can work much faster,
and he can have several machines going at once.
You'd never guess it, but a cow is a nervous, fussy
animal. She lets down her milk easily if the same per-
son or the same machine squeezes on her teats with the
same rhythm every day, but any kind of change or
hurry upsets her. Then she's hard to milk. And so Al's
machine is built with a very accurate timer which makes
the funnels squeeze exactly forty-eight times a minute.
A good farmer tries to make life calm and comfort-
able for his cows. Even the names for some things in
Al's barn have a comfortable sound. The place where
the cows wait to be milked is called the loafing pen.
The room where they stand for milking is kept per-
fectly clean, and it's called the milking parlor.
Before the machine is attached, the cows' udders
and teats must be washed clean. Al has fixed an upside-
down shower bath for his cows. He built a concrete pen
with sprays coming up through the floor. The showers
clean^the cows and make them feel so calm that he
never has any trouble milking them.
The fanciest milking parlor of all has a machine in
it called a Rotolactor. It is really a quiet, slow merry-go-
round. Cows amble up a ramp and step into stalls on
the gently moving platform. A man attaches milking
machines to them, one after the other. By the time each
cow has been carried halfway around the big circle, her
milk has been pumped out into a glass tank that sits on
a rack above her. A man takes off the rubber cups, a
gate opens in front of the cow, and she steps off onto
another ramp that goes from the center of the merry-
go-round, underneath it and out to the barnyard. Twen-
ty-five cows at a time can be milked on the Rotolactor.
Automatic gadgets empty the milk from the glass
tanks, wash them, sterilize them and get them ready for
the next round. All the time men are busy keeping the
stalls clean and tending to the machinery. Most dairies
milk the cows twice a day, but the Rotolactor milks
MACHINES FOR EVERY JOB
The Rotolactor was invented for one particular
kind of huge dairy. But farmers everywhere like to have
good machinery to do special jobs.
For hilly country, there's a plow that has one of its
blades higher than the other so it can work on a slope.
There are chisel plows that dig up hard soil by clawing
at it with strong steel fingers.
One farmer in Texas decided to make his tractor
do the plowing all by itself, after he had driven it once
around the field to give it a start. He invented a guide
wheel that went ahead of the tractor in the furrow he
had made. Now the guide led the tractor around in a
spiral that got narrower and narrower until at last it
stopped in the center of the plowed field. Another
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Texan, with a bigger field and more machines, had a
larger idea. He set three tractors loose without drivers,
one behind the other. Away they went, round and
round. If one traveled too fast and caught up with the
one ahead, they stopped. The only work he had to do
was go out and start them up again!
There have even been experiments in guiding plows
by remote control radio, the way airplanes can be
guided. The farmer just sits under a tree and pushes
buttons in a control box.
COTTON MEANS HARD WORK
Cotton is a crop that has always taken an enormous
amount of work. Even after cultivating machines were
invented, men had to go through the fields twice every
year and hoe out weeds around the plants by hand.
One farmer rigged up a contraption that made hoeing
easier. He hitched an air compressor to his tractor and
ran hoses from the compressor to four special hoes.
Then the escaping air jiggled the hoes in the men's
hands and saved the work of swinging them up and
Nowadays some of the big cotton farmers have an
easier way of solving the problem. They just keep the
weeds from growing in the first place. As the planting
machine drops the cotton seeds, it spreads weed killer
along each side of the row. This killer is a particular
kind of chemical that keeps the weeds from sprouting,
but it does not hurt the cotton. The only weeds that
grow in the field come up between rows where it's easy
for a cultivator to scratch them under.
At cotton picking time, machines now do the work
in many places. Cotton is ready to pick when the little
round heads of white fluff called bolls break open. Not
all the bolls on one plant burst at the same time. A man
who picks by hand can tell by looking which ones are
ready. Of course the machine doesn't have eyes, but its
tiny barbed steel fingers catch up only the opened
bolls. The fingers are fixed on a turning drum. They
pluck the cotton from the plant, carry it around to be
pulled off and blown through a big pipe into a large
basket behind the driver.
People have been trying for at least a hundred
years to invent a perfect cotton picker, and they
haven't succeeded yet. The machines still can't do as
careful a job as skilled men and women can do by hand.
Nobody could possibly do by hand all of the spray-
ing that protects farmers' crops. Mechanical sprayers
come in many shapes and sizes. The most usual sort for
big fields travels along behind a tractor, shooting chem-
icals out from nozzles in a pipe that is twenty or thirty
or even sixty feet wide.
Some of the special sprayers are queer looking
machines. One of them has six squirmy arms, bent in
different directions so that they get the chemicals un-
derneath leaves and on top as well. The kind that sprays
fruit trees pumps chemicals out of twelve pipes at once.
It works so hard and fast that farmers call it a cyclone.
Then there is a sprayer that can be used for several
different kinds of job. One day the farmer hitches it
up to a tank near cattle pens. As the cattle walk down
a narrow path between two fences, he sprays them
with a chemical that kills bothersome insects. Next day,
he may want to paint his fence. So he rigs the machine
up differently and shoots paint onto the boards.
All of this sounds as if everything that a farmer could
need must have been invented by now. The fact is that
there are new inventions coming along all the time, and
farmers themselves make many of them. Every day in
the week some farmer is likely to think up something
he needs, then go to work making it. Here is a sample:
Many farmers spe-
cialize in raising a kind
of corn called hybrid
corn. In order to make
it grow properly, they
must pick the tassels
off the tops of some of
the corn plants. Each
tassel has to be picked
by hand, and it's a slow
job in a big field. So
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one farmer rigged up a machine that gives four tassel-
pickers a comfortable ride all at the same time, and it
gets the job done much more than four times as fast
It would take a whole book just to list the other
machines that help different kinds of farmers. But here
are some that are fun to know about:
One clever contraption attached to a tractor grabs
hold of nut trees and gives them a hard shaking. The
nuts fall on the ground, ready for a kind of giant
vacuum sweeper to come and suck them into a truck.
Crops that grow underneath the earth need their
own sort of harvesting machine. There are potato dig-
gers and many others. The sugar beet digger works in
a particularly clever way. Machine fingers feel for the
beet tops. They set off a knife which cuts the tops off
while other fingers lift the beet out and put it on an
elevator which removes the clods of dirt as it travels.
Once in a while the machine makes a mistake and de-
livers a stone, or a chunk of mud at the end of the ele-
vator. Men do nothing but throw the junk away and
let the beets slide into the truck that travels alongside.
A farmer always has to keep an eye on what his
implements are doing, unless he has a helper who rides
along on machines like this big reaper. When the trac-
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tor pulls a cultivator or a planter, the driver must turn
his head often to see how the work is going. For a long
time, farmers complained that this was a pain in the
neck, and they really meant that their necks hurt from
turning so much. Some of them actually went back to
using horses, because they could either walk or sit be-
hind horse-drawn machines. So the farm machine
makers had to change as many of the machines as they
could, placing them beside the tractor or out in front
where the driver can watch what is going on.
Tractors themselves come in many sizes and shapes.
Some are built very high off the ground so they can
pass over tall crops without hurting the plants. Some
have four wheels that can be pushed close together for
work in one field and pulled wide apart for work in
another. Some have three wheels.
Mostly, farmers buy tractors the way people buy
automobiles. They pick a model they happen to like
and then argue that it's the best in the world. Of course,
a little light ''cub'' tractor is easier to handle than a big
one, but it can't do the hard work of a heavy model
with huge rear wheels and tires. And here's something
about the tires — farmers often fill them with water in-
stead of air to give them more weight when they grip
the ground. In winter, these farmers must put anti-
freeze not only in the radiator
but in the tires as well!
On enormous farms where
very heavy work must be done,
there are often crawler tractors
to do it. Instead of tires they
have caterpillar treads that give
a better grip on the ground.
Then they can pull a whole
string of plows the way you see
them in the picture, staggered
This kind of tractor was
first named caterpillar by only
one manufacturer. But people
liked the idea, and they began
to call all crawlers caterpillars.
A caterpillar is powerful
enough to push a snow plow,
too. Or it can bulldoze out a
hole for a watering pond or a
cellar for a new building.
Charlie is the man who can tell you about driving
a caterpillar tractor. He works in a city, helping to put
up big buildings, and he knows how to use other con-
struction machines, too. In fact, Charlie grew up with
machines, for his father and his uncles and his grand-
father were construction workers. It often happens that
families pass along their knowledge of building from
the older to the younger men, and they are very proud
of their skills. Charlie uses the caterpillar tractor with a
bulldozer blade to push heaps of earth and rock into
a pile, ready for the shovel to load on a truck.
People often call the shovel a ''steam shovel/' but
that's not its right name. You hardly ever see a real
steam shovel any more. Years ago the big digging ma-
chines were driven by regular steam engines. Before
they could start to work on a job, the men had to build
a fire in the boiler and wait until they had enough steam
pressure to make the shovel go. Of course, this wasted
a lot of time. So, when very strong gasoline and Diesel
engines came along, builders began using them for their
shovels instead of steam engines.
Many shovels and other construction machines ride
to work on long gooseneck trailers. They travel faster
that way than they could on their own crawlers. And,
in cities, the caterpillar treads might damage the pave-
ment. To load and unload a shovel, the operator sets a
short ramp of heavy planks against the trailer. Then the
shovel creeps up and down on its own crawlers.
The kind of shovel that's used on a job depends
upon the work that must be done. If a basement has to
be dug through hard rocky earth, Charlie may operate
a crowd shovel, which crawls down into the hole. The
shovel has a heavy dipper with teeth along the rim.
When it digs, it crowds its teeth down into the ground.
Charlie, sitting inside the cab, called the house, swings
the dipper outward and up, then dumps the load into
Another shovel digs in the opposite way. It's called
a pull shovel. The teeth dig down and toward the
driver. It can work from a bank and doesn't have to go
down inside the hole at all.
Sometimes Charlie uses a crane to get loose earth
out of a hole. The crane has a long boom with wheels
at the tip. Cables run over the wheels. Charlie fastens
a kind of bucket called a clamshell to the cables. With
its mouth open, the clamshell drops down over a heap
of rocks and earth. Then Charlie starts machinery that
pulls up on the cable. The jaws of the clamshell squeeze
together and come up with a load of earth. Now Char-
lie swings the whole crane around till the clamshell is
hanging above a truck. He pulls a cable that opens the
bucket, and the earth and stone tumble out.
After the basement for a building has been dug,
Charlie uses the crane for other jobs. Men hook the
cables to heavy steel beams, and Charlie lifts them into
No matter what he is doing, he has a lot to watch
out for. He must know which of four brake pedals to
use at any moment and which of four hand levers to
pull. One lever works the turntable which swings the
whole house around. One moves the boom up and
down. The other two control the cables.
At the same time, Charlie must watch what's going
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on outside. A man stands on the job giving signals.
Thumbs up mean 'Take the boom up.'' Thumbs down
mean 'Tower the boom.'' When the signal man points
up with his first finger, it means ''Raise the cable." If he
wiggles the finger, it means "faster." When Charlie is
lifting a beam and has to hold it for a while in the air, he
says he "takes a strain and dogs it off." Dogging is his
word for setting the brake on the cable.
Things are always likely to fall around a construc-
tion job, so the men who work on the ground have steel
caps in their shoes to protect their toes. They wear steel
helmets on their heads, too!
As the building goes up, Charlie's crane lifts loads
higher and higher. After a while he has to put a jib on
the boom. This is an extension that makes it longer.
When the building goes too high for his crane to reach,
Charlie works another crane. It sits on top of the build-
ing's framework and reaches down from there.
After Charlie lifts a big steel girder into position,
other men bolt it in place then fasten it tight with
rivets. A man called a heater gets the rivets red-hot in
a fire. Using tongs, he tosses them one at a time to the
catcher who reaches for them — not with a mitt but
with a kind of cup. The catcher pokes a rivet in a hole,
and two other men fasten it tight. One of them, the
bucker, holds the rivet in position with a bar, and the
rivet man pounds the other end flat with a rivet gun.
(The gun works like a jack hammer, and it makes an
When you're down in the street, it's hard to realize
that there may be a heavy wind blowing across the bare
girders of a tall new building. High in the air, men have
to keep their balance on narrow places and walk with
sure feet. There are families who specialize in work far
above the solid ground. Boys learn from their fathers
how to walk safely without being afraid — although
almost everyone is frightened at first. And, of course,
everyone is careful. In New York a group of Mohawk
Indians have worked on many high buildings where
men like Charlie did the beginning work.
Once in a while Charlie helps to wreck an old
building before putting up a new one. First, a crew of
men go in and take away everything that can be used
again or sold for junk. With specially made crowbars,
they pry away floors and door frames. They take out
furnaces and plumbing fixtures.
Then Charlie gets to work with
his crane. At the end of a cable
he fastens a heavy steel ball,
called a skull cracker. Then,
swinging the boom, he bashes the skull cracker into the
wall of the old building. Over and over, the ball strikes
the mortar and bricks. Cracks spread, and big chunks
of the wall start tumbling to the ground. In a little while
Charlie and his machine have made a heap of rubble
out of a house that it took dozens of men to put up.
BUILDING A ROAD
Once Charlie worked on a road-building job. There
he used a crane and a shovel and many other machines
besides. This particular road had to cross a big swamp
near the ocean. So the first problem was to fill up the
swamp with something solid. In order to get enough
earth and rock for the fill, men would have had to tear
down a whole mountain. Instead they called in suction
dredge machinery for the job. The huge pumps sucked
sand from the bottom of the sea and poured it through
pipes onto the swampy ground. When the water drained
away, millions of tons of fine white sand were kft.
Charlie helped level the sand off with a bulldozer.
Then he moved on to a place where a hilly spot had
to be leveled. There he drove a carrying scraper, a
machine with a scoop between its front wheels and
its rear wheels. The sharp scoop scraped up a load of
earth, and Charlie drove off to dump it in a low spot.
When he got there, a pusher blade at the back of
the scoop pushed the earth out. Round and round he
went, without having to stop for loading or unloading.
Other men used a different machine like the one
in the picture. This earth mover carried more in one
load than the motor scraper, and it was better for haul-
ing earth longer distances. For very short hauls, Charlie
drove a fast little tractor. At least it looked small com-
pared to the giant machines. It pushed a scoop in front
of it like a shovel, then lifted a load, turned swiftly and
dumped the earth where it was needed a few yards
Charlie's road was going to be a special highway for
speedy traffic. In order to make it as safe as possible,
the crossroads had to be lifted up over the new high-
way. Crews of men built these overpasses. First they
used the huge earth-moving machines to make little
hills on each side of the highway. Then they built
bridges of concrete and steel between the hills.
At one place, there were two houses on the exact
spot where the hill for an overpass had to be made.
Instead of tearing the houses down, moving men just
carried them away with the furniture still inside. First
they raised the houses off the ground with jacks. Next
a tractor backed a wide, low trailer up close to each
house. Using special machinery and rollers, the men
eased the whole building onto the trailers. That same
night, the houses were set down on new foundations,
and the people went right on living in them.
At one place, a big ledge of rock was in the way of
the new road. Men called powder monkeys blasted the
ledge to smithereens with explosive. Then Charlie came
in with his caterpillar tractor and a rock rake. Unlike
a garden rake, which you pull, Charlie's rock rake
scratched up rocks and pushed them ahead of it. He
shoved all the loose chunks of stone away, but several
big ones were too far underground for the rake to pry
them loose. So Charlie put a ripper on behind his
The ripper had strong prongs that could dig down
deep and get a good hold on a boulder. The frame that
held the prongs was hollow. For very heavy work,
Charlie filled the hollow frame with sand to give it a
lot of weight so the prongs wouldn't slip. To pry out
the very largest boulders, Charlie sometimes got an-
other driver to hitch his caterpillar onto the ripper.
Then the two tractors, chugging together, did the job.
After the bulldozers and scrapers and rakes had
built a rough bed for the highway, Charlie helped to
smooth it down and get it all ready for finishing. He
used a long six-wheel motor grader for the job.
The motor grader had its Diesel engine in the rear.
above the four wheels that did the pushing. The guid-
ing wheels were way off at the front, and in between
was the scraping blade, placed where Charlie could
Charlie could set the blade at almost any angle, just
as a barber can tilt a long-bladed razor. And Charlie was
proud of the way he had left the road almost as smooth
as a barber leaves a man's face.
Charlie could play tricks with the motor grader's
front wheels, too. Besides steering them in the ordinary
way, he often made them lean over toward the right or
the left. To look at them, you'd think they were
broken, but they were only tilting to do a special job.
They were actually in a tug-of-war with the blade and
the earth it was pushing. The weight of the earth against
the blade pulled the grader toward one side. But the
leaning of the wheels pulled in the opposite direction.
So the two pulls balanced each other. Charlie could
guide the grader in a straight line without having a
wrestling match with his steering wheel.
Charlie leaned his wheels when the grader went
around a bend in the road, too. They helped the long
machine to turn easily. If he had to back into a ditch,
he didn't worry. The great wheels adjusted themselves
to the sloping earth. All six wheels stayed on the
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ground, and the machine never got hung up the way a
four-wheeled automobile would.
When the earth had been smoothed down, it was
time to put the hard surface on. Trucks brought in
crushed rock to make a solid bed. Concrete mixers cov-
ered the rock with concrete. And asphalt spreaders put
a coat of asphalt on top.
Wherever the asphalt wasn't spread evenly, men
with rakes finished the job by hand. Then came the
tandem roller to pack it down and make the surface
A Diesel engine moved the roller's great weight
quickly back and forth over the asphalt. In no time the
road was as smooth as a table top. If the driver wanted
to, he could turn his seat sideways. Then he could eas-
ily see whether he was guiding the roller straight for-
ward and straight back.
Many people call road rollers ''steam rollers.'' That's
because the first ones really were driven by steam en-
gines. Men have a lot less fuss and bother with a mod-
ern Diesel-engined tandem. There's no need to start the
fire or shovel coal to keep steam up. You can still see
some steam rollers at work, though, because they are
strong machines that last a long time. But when one
wears out, it is replaced with a modern roller.
After the roller finished smoothing all the asphalt
down, Charlie's road was ready for traffic, but the job
still wasn't quite done. All along the highway the ma-
chines had left bare banks of earth. These had to be
protected from the weather — just the way a house is
protected with a coat of paint. The best coat for the
earth is grass of one kind or another. So Charlie turned
gardener. In some places he used the motor grader
again to prepare the soil so that seed could be planted.
With the blade of his grader hung away out at the side
and pointed up in the air, he smoothed off the steep
banks. Running along the edge of the road, he filled in
the soft shoulders.
Then a seed-planter sowed the grass. And finally
Charlie used the strangest machine of all. It chugged
and puffed and spit out great mouthfuls of hay, which
fell over the newly-planted grass! The hay protected
the grass seed and kept it moist until its roots were
growing strongly in the soil.
MORE ROAD WORK
The road was finished now, but some of the ma-
chines still had work ahead of them. In fact, road work
is never ended.
All summer long, tractors pull mowing machines
beside the highways, cutting the grass. Brush and small
trees must be kept cleared away so that drivers can see
ahead. In winter, the motor graders and the snow
plows can keep the road clear. But in places where
heavy snow piles up into drifts, caterpillar tractors often
push special snow plows that eat through the drifts
with powerful whirling blades. With one motion these
plows dig out the snow and throw it off to one side of
The caterpillar treads work better in snow than
wheels with tires. So the ''cats'' are used all winter long
in the Far North. There they even pull whole trailer
trains on runners. The one in the picture is hauling
Muskeg schooners, which are really trailer houses on
sleds. Muskeg is an Indian word for swamp. The cats
pull the schooners over frozen, snow-covered swamps.
You may wonder why anyone wants to use a trailer
home in the roadless wastes of the Far North. The fact
is that men work there the year round, prospecting for
oil. When they think they have located oil there or
anywhere else, well-drilling machinery goes to work.
Everybody knows that oil wells and derricks go
together. The tall derrick towers are needed to hoist
drilling equipment in and out of the hole.
When men start to drill a well, they fasten a cutting
tool, called a bit, to a piece of pipe which hangs upright
in the derrick. Machinery turns the whole thing round
and round, so that the bit grinds down into the earth.
When one length of pipe, called a joint, has almost dis-
appeared into the hole, men screw another joint onto
the top of it. Now the engine turns the double-length
pipe, and the bit digs down deeper.
Men, working on the floor and high up in the der-
rick, hoist more and more joints into position and screw
them together as the bit goes on down. After a while,
the bit gets dull. A new one must be put on. So, strong
cables that run over wheels at the top of the derrick
begin lifting the whole string of pipe out. Joint by joint,
they unscrew the pipe and stack it out of the way.
When the last joint comes up, men change the bit.
Then back the pipe goes, joint after joint, into the hole.
Wells must often be drilled more than two miles
deep before the bit breaks through into an underground
reservoir of oil. That means that the string of drilling
pipe must be two miles long. The machines that help
to handle it are very strong, but on many rigs, men
have to use their own muscles a great deal, too.
For deep drilling, the most modern rigs have a lot
of fine new machinery. Automatic tongs take a tight
grip on the drilling pipe when it is being unscrewed.
Men used to work the tongs by hand. Mechanical hands
now keep the bottom joints from dropping back into
the hole, and arms high up in the derrick do the job of
stacking the pipe.
The skillful men who work with the pipes and the
machinery call themselves roughnecks. The driller is the
one who actually controls the drilling pipe. He never
says he is digging a well. He says he is ''making hole.''
Almost all deep wells are now drilled by the turning
pipe and bit, which are called a rotary rig. But some-
times you can see an old-fashioned cable rig at work.
It makes hole with a bit that pounds its way down into
earth and rock. A cable raises the bit, and then lets it
fall down with a bang that chips away a hole. On both
kinds of rig, the hole is cleaned out with water. The
water turns the rock dust into mud, which is then
The cable rig idea is about two thousand years old!
That long ago Chinese drillers made water wells, salt
wells and even oil wells. The picture shows what one of
these ancient rigs was like.
Look first of all at the long board attached to the
rope that goes up over a roller and down into the well.
Then look at the platform behind the board. Men
jumped from this platform down onto the board. That
jerked on the rope and pulled the drilling bit up in the
well hole. When a man jumped off the board, the bit
fell down and chipped away some rock. Round and
round a whole crew of men raced, jumping onto the
board and climbing back onto the platform as fast as
they could. Still it took a long time to drill a well —
sometimes as long as ten years.
Now look at the big wheel turned by a bull at the
right. This wheel lifted the pipe made of hollow bam-
boo that you see at the left. The pipe was actually a
bailer. Every once in a while the men poured water into
the hole, let the bailer down and hauled up mud. Then
the bit could go on drilling. Oil workers today still call
the wheel which winds up cable ''the bull wheel.''
When a well brings in oil, a new group of men and
machines go to work. They lay a pipeline, through
which the oil can be pumped to factories called re-
fineries. Some pipelines are hundreds of miles long.
After surveyors have decided just where the line
should go, bulldozers clear away brush, push over trees,
heave big boulders to one side, making a wide pathway
across country. In many places, the pathway is good
enough for trucks to follow. They bring in lengths of
pipe and lay them down end to end. Where the going
is rough, a caterpillar tractor carries the pipe, one length
at a time, hanging from a side-boom.
Now welding crews go to work fastening the ends
of the pipe-lengths together. When they have finished,
the ''hot-dope gang" comes along. They are men who
cover the pipe with a wrapping and then with a hot
asphalt mixture to protect the metal.
Meantime, a wonderful machine called a trencher
has been at work. This is a cat attached to a rig which
looks very much like an old-fashioned water wheel.
Each bucket on the wheel has steel teeth. The cat turns
the wheel and pulls it forward. The buckets scoop up
earth, and spill it out onto a belt that dumps it in a
heap at one side. The trencher plugs ahead, uphill and
down, digging a ditch just the right width and depth.
Following behind the trencher, cats with booms
hoist up the snaky pipeline and ease it over into the
trench. Finally, bulldozers backfill the trench. That is,
they cover the pipe with the dirt that the trencher left
alongside. On one job, the men had to work at top
speed in the desert and in rocky, mountainous country.
They were all so glad they'd finally succeeded in get-
ting the pipeline built that they put on a celebration.
Whooping and hollering, they tossed their sweat-
stained hats into the trench in front of the bulldozer as
it backfilled the last few feet of earth.
Even after that there was one more tool that had
work to do before oil could be pumped through their
pipeline. It is a peculiar gadget that looks like a bunch
of cowboy spurs hooked up with pieces of tin can and
some old plates. The weird contraption is called the
go-devil, and it has the job of traveling, perhaps hun-
dreds of miles, inside the pipe, pushing out anything
that could clog the line. Water pumped into the line
behind the go-devil forces it through the pipe.
In one line, the go-devil brought out chunks of
wood, pieces of rock — and several rabbits, skunks and
rattlesnakes that had decided the pipe would make
good headquarters! Now the powerful pumps could go
to work shoving oil through the line.
Oil pumps today are much better and stronger than
the first pumps ever built, but they are direct descend-
ants of the ones that were invented for use in English
coal mines long ago. In fact, those early pumps were the
great-granddaddies of all modern machines.
Coal miners in England had dug so far beneath the
surface of the earth that the shafts and tunnels were in
danger of filling up with water. Neither manpower nor
the power of horses hitched to pumps could do the
tremendous job of keeping the mines dry. Something
much stronger was needed. In order to find a new kind
of power, inventors began experimenting with steam.
The first workable steam engines were made to pump
out coal mines more than two hundred years ago.
After a while steam engines began to pull trains over
rails and drive ships through the water. They ran
threshing machines on farms. Then inventors used their
new knowledge about power to make other kinds of
engines driven by gasoline or electricity or oil.
At last some of this new machinery began to work
its way back into the mines. Power driven elevators
carried the men up and down shafts to their work. But
the miners still did all the coal digging and loading by
Today many miners use power-driven drills for dig-
ging. Mechanical loaders pick up the loose coal and put
it into small cars on the tracks in the tunnel. A little
electric locomotive pulls the cars away to the elevator
which hoists them up above ground.
The most remarkable digger of all is the one you'll
see on the next page. It rolls along a track deep under-
ground until it comes to the place where its operator
wants to cut coal. He pushes a control, and the ma-
chine's long neck reaches up. The cutting head, at the
end of the neck, starts biting into the coal. The head
does its work much faster and easier than men with
hand tools ever could.
Outside the mine, machines sort the coal according
to size and load it into railroad cars.
Unloading machinery empties the cars in many
places, too. There's one coal yard where a woman, push-
ing buttons, controls machines that do everything —
unload cars, store the coal according to its size in tall
bins, and load the trucks that will deliver it to cus-
tomers. This is how the yard works:
Each railroad car empties its coal in a stream onto a
moving belt. The belt carries the coal to a machine
called a giraffe, which works like an escalator. The
giraffe lifts the coal into a tall hopper.
The woman who runs the coal yard sits in an office
with a big window, where she can look out and see
everything that's going on. When a truck has backed
up to a hopper, ready to load, she pushes a button. Coal
drops down out of the hopper onto another giraffe
which lifts it into the body of the truck. As soon as the
truck is filled, push goes a button and the loading stops.
LOADERS, LIFTERS AND SUCH
Moving belt machines work at other jobs, too. They
load sand into trucks and cargo into ships.
On some piers, huge vacuum cleaners empty ships
full of sugar or wheat. At ports on the Great Lakes,
machines reach down into ore-carrying ships and un-
load them with great speed. At the end of each of these
unloaders hangs a clamshell bucket. Just above the
bucket is a little room where a man sits and watches
what goes on. He signals to the operator, telling him
just where to drop the bucket so it can pick up a mouth-
ful of ore. The ship can be unloaded by two men who
do nothing but signal to each other and push levers.
But usually there are several machines working at the
same time so that the job goes as quickly as possible.
When iron ore has been turned into steel bars or
wheels or gears, another kind of lifter can handle them.
This one does its work with a huge electro-magnet that
holds heavy weights when electricity is running through
it. The operator drops the magnet onto the load of iron
or steel that he wants to lift. Then he turns on the elec-
tricity which makes the magnet and the piece of metal
stick together. The operator moves the load wherever
it is supposed to go. Then he turns off the electricity.
The magnet lets loose and is ready for another job.
MACHINES FOR LUMBER, TOO
Machines dug and loaded and delivered the coal
that keeps your house warm. Machines helped cut the
lumber that went into building your house, too.
Far out in the woods, power-driven saws sliced
quickly through the trunks of great trees. Caterpillar
tractors hauled the logs out along rough forest trails.
Perhaps the cats, using booms, lifted the logs onto
extra-long trailers behind trucks and started them on
the way to the sawmill. Or the cats may have snaked
the logs to a river so they could float downstream to a
No matter how the logs reached the sawmill, they
were put at last onto belts which pushed them against
huge whirling saws. A whole set of saws, all whining
and screaming at once, turned the thick log into boards.
Other machines planed the boards to make them
smooth and then cut them to exactly the right sizes.
Finally lift-trucks picked up
great piles of board at once,
whizzed them away and hoisted
them elevator-fashion into high
The operators of most machines sit where they can
see what they are doing, or where they can get signals
from helpers. But there is one that does things in a new
way. Its operator just watches television in his cab. He
never sees the parts of his machine at work. Instead, he
looks at the television screen. A television camera on
the roof of the building photographs what is going on
below. This is what the eye of the camera sees: One
machine that gathers up pieces of scrap metaf and
dumps them into a squeezer; the squeezer that presses
the scraps into neat bundles; a conveyor that loads the
bundles into a railroad car.
The operator watches the moving picture. Then he
pushes levers that control the loaders and other levers
that send a car on its way when it is full. The only thing
he can't do is switch on a regular TV program and
watch a show while he works!
The time may come when people who operate
other kinds of machines will find television helpful in
many ways. Meantime, scientists who know how tele-
vision works also know how to make the most wonder-
ful machines of all. Instead of saving muscle-power,
these machines save brain-power. They solve very com-
plicated mathematical problems at lightning speed. In
fact, they are called ''thinking machines/' They add,
subtract, multiply, divide and do figuring that many
college professors can't even do.
Partly for fun, and partly to discover new things,
the thinking-machine experts have also invented me-
chanical animals. They've made turtles that can walk all
around a room without bumping into anything. They've
made a little wire-whiskered mechanical mouse that can
actually sniff about until it finds something it is sup-
posed to find — just the way a real mouse sniffs out a
piece of cheese. The machine-mouse even ''remembers"
where it went, and it runs straight to its cheese the next
The machines you've read about in this book are
mostly outdoor machines, operated by one man or a
small crew of men. These are only a few of the mar-
vellous inventions that you can find at work every day.
Of course, there are hundreds and thousands of others
in factories, making cloth, shaping automobile parts,
printing books, doing the important work the world
needs done. But, no matter how marvellous and com-
plicated they are, they will never be as wonderful as the
men who have invented them and built them and used
them. When we talk about machines, we're really talk-
ing. about people.
Some machines resemble animals in
the way they look or the things they
do, and so they have animal names. Be-
sides the caterpillar with its crawler
treads and the crane with its long neck,
here are some others:
ALLIGATOR GRAB — a tool used to
pick up things that get dropped
into oil well holes.
CAMEL-BACK CRANE — this one has
a hump in its boom.
FISHTAIL BIT — a drilling tool which
is shaped like a fish's tail.
KANGAROO PLOW — a plow equip-
ped with strong springs so it can
hop over rocks or tree stumps, in-
stead of getting caught on them.
SHEEP'S FOOT TAMPER — a heavy
road roller with spikes that pack
earth down, the way a flock of
WORM LOADER — a long screw that
twists round and round to push its
airplane duster, 26
asphalt spreader, 65
baler, automatic, 26-27
beet digger, 42
boom, 9, 49, 51,55, 74,
"box seat," 22
bulldozer, 45, 55, 51,
6\, 67, 7 A, 77
bull wheel, 73, 74
cable rig, 72
caterpillar, 45, 46, 60,
67, 68, 74, 77, 85
cement mixer, 65
chicken picker, 24-25
Chinese drillers, 73-74
chisel plow, 32
clamshell, 49, 84
coal digger, 81
coal loaders, 81
coal mining, 9, 78-83
corn cutter, 25
corn picking machine,
corn planter, 19
cotton picker, 37-38
cotton planter, 37
crawler tractor, 45
crawlers, 10, 48, 49
crowd shovel, 49
"cub" tractor, 44
cutter heads, 15
cutting head, 81
Diesel engine, 47
driverless plow, 32-35
earth mover, 58
egg machinery, 24
egg sorter, 24
farm machines, 18-45
gooseneck trailer, 48
grass planter, 26
hay baler, 26-27
hay blower, 67
hay rake, 27
hay stacker, 28-29
hoe, compressed air,
"hot-dope gang," 74
house moving, 58
magnet crane, 84
"making hole," 72
manure scoop, 24
mechanical mouse, 89
milking machine, 29-32
motor scraper, 57
mowing machine, 26
Muskeg schooner, 69
nut harvester, 41
oil wells, 69-74
ore unloaders, 84
overhead crane, 10
"package job," 22
piggy-back crane, 10
pile driver, 1 3
plow, 17, 18, 32, 33,
post-hole 5igger, 16
potato digger, 42
powder monkey, 60
power shovel, 47-48
reaper, 22, 42
rivet gun, 53
rivet man, 53
rock crusher, 12
rock rake, 60
rotary rig, 72
seed planter, 67
shovel, 9, 47-48, 49
signals, 52, 84, 88
silage blower, 26
skull cracker, 54
snow plow, 45, 67
steam engines, 80
steam roller, 66
steam shovel, 47-48
suction dredge, 57
tandem roller, 65
tassel picker, 40-41
television, 88, 89
tomato planter, 22
tractor, 17, 18, 44, 45,
trailer houses, 69
turntable, 5 1
two-gang plow, 18
vacuum unloaders, 84
welding crew, 74
well drilling, 69-74
The author and the artist wish to thank the following for their help in making this book
possible: Miss Elsie Eaves, Manager, Business News Department, l:.ncUnccrincl 7\'ews-Kt'cc>rd ,■
Margaret Gossett; Mr. Harold Spitzer,- Jbc Lamp, published by the Standard Oil Company
(New Jersey); the Caterpillar Corp.; the General Motors Corp., the New Jersey Bel! Tele-
phone Co.; the Florida Land Clearing Equipment Co.; the Walker-Gordon Laboratory Co.;
the many manufacturers of digging, road-building and other specialized machines; a bumper
crop of tractor and farm implement makers; and farmer friends who proudly showed their
equipment in action.