Childrens Illustrated Encyclopedia

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With

the wind to the

side of the boat, the

sail is drawn in more

tightly. The boat travels fastest

with the wind in this position.

ShipS and boatS

464

Hydrofoil

A boat’s engine has to work hard to overcome the

resistance of the water. Light, fast boats called hydrofoils

avoid this problem because they rise up on skis at high

speeds. With the hydrofoil traveling so rapidly, water

behaves as if it were a solid, so the hydrofoil skims over

the water surface just like an airplane wing in air.

Hide boAt

About 6,000 years ago the Ancient egyptians

used boats made of a wicker framework covered

with animal skins. in about 3200 bce, the

egyptians invented sails.

trireme

the Greeks invented the trireme (above) in

about 650 bce. it had sails and lines of rowers

to carry it along at speed. the romans

built similar ships for trade and war.

CLipper

Fast sailing ships called clippers (above)

appeared during the 19th century, the

height of the age of sailing. they carried

many sails and had sleek lines to

increase speed. Clippers were

used mainly for trade.

SteAmSHipS

oceangoing steamships (below)

took to the seas early in the 19th

century. the earliest vessels had

paddles connected to the engine

and sails to gain extra speed in

high winds. Ships with

propellers entered

service during

the 1840s.

KindS oF boAtS

different boats have different uses. many boats, such

as yachts, are pleasure craft; tugs and

fishing boats, however, are the

workhorses of coastal waters.

tuGboAt

tugs tow larger vessels, guiding

them through difficult or shallow

waters at sea or on inland

waterways, such as canals.

With the wind behind the

boat, the sail is stretched

out across the boat.

A sailing boat cannot

travel directly into the

wind. Instead, it must

follow a zigzag path.

This is called tacking.

Direction of movement

Direction of wind

Wind pushing on sail

Centerboard

prevents the

boat from drifting

with the wind and

stops the boat

from capsizing.

Any force can be divided into

two parts at right angles to

each other. The part

along the length of

the boat drives

the boat forward.

Air rushing past the

sail produces a

force that tends

to move the boat

at right angles

to the wind.

HoW A boAt SAiLS

modern sailing boats do not need the wind

behind them to move—they can travel in almost

any direction. in the same way that

air rushing over the wings of an

airplane produces an upward force

called lift, wind moving past a sail produces a force

at right angles to the sail. Adjusting the sail makes

the boat move in different directions.

poWerboAt

powerboats are small, fast boats

driven by powerful gas or diesel

engines. they are used either for

pleasure or for racing.

YACHt

Yachts are pleasure boats. they

have engines or sails. racing yachts

are built purely for speed and are

made of strong, light materials.

HiStorY oF SHipS And boAtS

the development of ships began more than 6,000 years ago

with rafts and reed boats, and continues today with the

introduction of nuclear-powered ships

and boats made of light, strong plastics.

Wind rushing past sail

The boat heads into the

wind with the sail drawn

in as tightly as possible.

Groups of rowers were positioned on two levels.

Direction of

movement

Find out more

navigation

oceans and seas

ports and waterways

Submarines

technology

Wind

US_464_Ships_Boats_2.indd 464 22/01/16 4:48 pm