Moving machines
Machines have lots of different moving parts.
Looking at the inside of a clock can show you how many parts there are.
There are four basic parts inside many of these machines-cranks,gears,levers,and pulleys.
A crank is made from a handle,a thin rod, and supports.When you turn the handle,
the rod moves.Many machines use cranks, including mechanical pencil sharpeners,bike
pedals,and sewing machines.
Gears are like wheels with teeth.When the gears turn,the teeth connect to make them move.
Gears can make something move faster or slower.Clocks,
multi-speed bikes,and music boxes all use gears.
A lever is a strong,straight object that sits against a support.
When either end of the lever is pushed down,the other side moves up.
There are several types of levers.Scissors and seesaws are both examples of levers.
A pulley is a machine made from a wheel and a rope or chain.
The rope or chain is pulled over the wheel and it helps lift heavy objects easily.
Elevators and wells use pulleys
Most machines only move when someone uses them,but automata can move on their own.
In the past, automata were simpler.Some were even toys!
Cuckoo clocks and wind-up dolls were popular automata before robots and automatic cleaning machines.
People could turn a key or pull some strings and see the toys give a performance!
The designers were usually clock makers or inventors because they understood how the machines worked.
Designers had to use their imaginations to make the machines look and move like real people or animals.
It often took many people and a lot of hard work to build one.
This silver swan is at the Bowes Museum in England.It is made from many pieces of silver and gold.
The river is made from glass rods.When someone turns the crank, the machine starts.
The gears under the swan turn the glass rods,so it looks like moving water.
Then,the swan turns its head and pulls a silver fish from the water.It even plays music.
Some automata need someone to press a button or put a coin in the machines to make them work.
They can be very interesting to watch.There are automata in many places in our lives:
in art museums,toy stores,and homes.These machines can be useful,fun,or both.
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