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Introduction

The Roman Empire is one of the greatest ancient powers in the world

history. In its heyday of the Roman Empire, its territory was extended to

Europe, Asia and Africa. Among all the ancient Roman leaders, Julius Caesar

was regarded as the most outstanding military genius, politician and

inventor. He was a great military leader with excellent military strategy. He

led his army to win numerous battles. If we could travel back to ancient

Rome, we would marvel at the ingenious design and creativity of Julius

Caesar and ancient Romans. By applying basic principles of science, they

invented many war machines and large machinery both for attack and

defense purposes and constructed magnificent structures. Nowadays, we

still apply those knowledge and technology that inherited from this great

empire in our daily lives.

"Julius Caesar – Military Genius and Mighty Machines" is an exhibition that

integrates science and history. It is divided into four areas including

"Military Genius", "All Roads Lead to Rome", "Building Rome" and

"Entertainment and Lifestyle". It features over 40 models of ancient

offensive and defensive war machines, military equipment of Roman

soldiers, ancient surveying and construction tools, ancient maps and books,

model of the Colosseum and ancient Roman coins etc. Through these

interactive exhibits, computer animations and real object displays, visitors

can have a glimpse of the Roman Empire 2,000 years ago, and have an

understanding of the military talent of Julius Caesar as well as the advanced

construction technologies of ancient Romans from a scientific perspective.

Exhibition is created by The Artisans of Florence – NICCOLAI S.N.C. (Firenze)

Exhibition Period: 7.12.2012-10.4.2013

Venue: Special Exhibition Hall, Hong Kong Science Museum

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Learning Guide

This exhibition is suitable for primary and secondary students. Teachers can make use of the exhibition to cover strands such as "Energy and Change" and "Science, Technology and Society" in the subject of General Studies of the Primary School curriculum. The exhibition can also supplement the "Force and Motion" module in the subject of Combined Science and Physics in the New Senior Secondary curriculum.

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Abstract

1) War Machines

Victory in a war hinges on several factors: tactics of the leader, quality of

soldiers and the most important of all - strong and effective weapons. In

ancient warfare, equipment of soldiers played a significant role: uniforms

helped to boost morale of the soldiers; highly protective helmets,

arc-shaped shields, rigid armor, daggers, swords and spears were useful

weapons in the battles. The ingenious military strategy together with the

famous "tortoise" formation of Roman soldiers rendered them formidable

to their enemies. The Roman Empire therefore expanded her territory to

the coastal area of the Mediterranean Sea.

All weapons used at that time were mainly human driven. Power was stored

and released to become a strong and effective weapon. Today in physics, we

define the energy stored as potential energy and the released energy in

motion as kinetic energy. Energy is interchangeable but will not be reduced.

That's the law of conservation in physics.

A) Onager

The Onager in the exhibition is an example. It has to be wound up to store

the potential energy. Then it is aimed at the enemy and fired to release as

kinetic energy.

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B) Ram in Testudo

The Ram in Testudo used for breaking

through the fortification, which is the

gate and walls of the enemy’s castle, is

another example using potential energy

(to swing the ram backwards and push

forwards).

C) Pile Driver

The Pile Driver tower using soldiers’

power to lift a weight (potential energy)

with the help of pulleys directing at a

precise location is another example. By

nailing down (kinetic energy) heavy piles

into the river bed, Roman soldiers built

bridges over rivers so that they could cross

them quickly.

D) Assault Tower

An Assault Tower served as a fast and safe

pathway for soldiers to climb over the wall.

By attacking the enemies both from the

top and the bottom, Roman soldiers

captured castles effectively.

2) All Roads Lead to Rome

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2) All Roads Lead To Rome

The vast pieces of lands that were conquered by the Roman army had to be

managed and controlled carefully and watchfully. Even today, the renowned

Roman Roads have still retained their glory. Roman roads, which are

endurable, connected all areas of the Roman Empire, enabling the central

government to control all news, information and resources of her

conquered lands.

Roman roads were built of local materials. The foundations were large hard

stones. The upper layer was paved with smaller stones and then the surface

was paved with pebbles. To avoid forming puddles, the road surface was

slightly elevated at the center, diverting water to ditches on the roadside.

Pavements were built on both sides of roads. To facilitate pedestrians in

walking across the road, steps were built on the roadside.

At certain point, a milestone was erected to indicate the distance to the

nearest city. To shorten the distance between two places, all roads of Rome

were straight. How did the ancient Roman government design and

construct such large-scale facilities two thousand years ago? The answer

was very simple, by observation in daily lives and out of need.

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A) Odometer

This instrument measures the distance

travelled by a cart based on the number

of turns and the circumference of the

wheel. When the wheel moves, it will

turn the small gear which in turn drives

the large gear to spin slowly. Pebbles

were put along the slots of a wheel and

after travelling a certain distance, a

pebble will drop into a container. By

counting the number of pebbles dropped,

the distance travelled was then known.

It was then carved on the milestone on the roadside.

B) Groma

By observing the phenomenon that a string

carrying a weight will always hang down

perpendicularly to the ground, the Romans

invented this Groma to make straight lines.

This is based on the principle which is called

gravity today. Four plumbs of the same

weight were adhered to the strings hanging

from the four corners of a wooden cross.

When an observer saw the two opposing

plumbs in a line, a straight line could then

be drawn. Interestingly, the target might be

a partner raising a stick, or smoke billowing up in a forest.

With these simple machines, the Romans built roads of a total length of

8,000 metres along the coast of the Mediterranean Sea, attracting tens of

thousands of visitors from all over the world for sightseeing.

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3) The Building of Rome

Soon after the Romans captured an area, they would start to rebuild and

construct the city based on the blueprint of Roman architecture, such as

colosseums, temples, aqueducts, columns, walls, castles, triumphal arches.

On the one hand, new citizens benefited from these constructions and

facilities. On the other hand, these magnificent structures demonstrated

power and prestige of the Roman Empire to the newly conquered people. By

winning the allegiance of these citizens, the Romans gained control of the

lands.

A) Crane with Treadmill (Calcatorian Crane)

According to record, this machine

can carry up to 20 tonnes of load.

It was driven by humans or

animals with the aid of pulleys. By

its side was a big wheel that can

accommodate 4 to 5 people to

work out the winding.

B) Ball Bearing

This bearing was believed to fit under the crane,

for the purpose of turning the crane around for

loading and unloading goods next to the pier. This

turntable applied the principle of friction. Small

metal balls were inlaid all around the rim of a

wooden round plate. Another plate, of the same

size, was then put on top of it. The contact area

between the two plates was reduced and hence

friction was much lowered. As a result, the turntable can be easily spun.

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C) Noria Hydraulic Energy Wheel

Water is an invaluable resource. Ancient

Romans cleverly used watermills to draw

water from nearby rivers, delivering it for

daily consumption or irrigation. Noria

Hydraulic Energy Wheel was constructed

near a river. Powered by current, buckets

of the wheel would be filled up with

water. Then they would be carried to the

highest point where water would be

poured out to a container for later use.

Extending the idea, gears can be added

to the device to produce a machine for

grinding grains. By cleverly utilizing the

force of nature, the Romans in ancient time enjoyed quality living.

D) Potter's Wheel

Potter's Wheel was a machine that

solely relied on man power. It was

powered by the potter, who slowly

turned and controlled the stepping

board by foot. A vertical axle of this

board was connected to the upper

disc which finally gave a speedy

rotation to form pottery which was

rounded and made more symmetrical

in shape. The faster the rotation, the

longer the continuity of the disc

spinning and hence the more

control of making the pottery. Animal fat would be applied to the axle to

reduce friction so as to increase the speed and maintain the continuity.

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E) Roman Arch

Arc-shaped architecture was invented by

Greek but Roman made it famous by building

them all around the world, marking the

glorious era in Roman history. To make an

arch, workers had to erect a temporary

arch-shaped scaffolding for support. Then

bricks would be laid on this arch. The last

piece at the centre was the keystone, which

allowed weight to be evenly distributed on

the foundation. In such way, lesser materials

made way for more space and hence more

levels could be built. Aesthetically, an arch structure gives people an

impression of spacious, harmony and splendid. Arch structures are common

in monuments, bridges, aqueducts and drains, colosseums, temples and

palaces. Its application extends to dome structure which is a key element in

architecture.

F) Roman Aqueduct

Romans used water a lot.

Historical remains of splendid

baths and fountains all

reflected their passion and

desire for luxurious living. The

design of aqueducts was based

on the principle of gravity,

diverting water from highlands

or mountains to the city. By

using excessive labour (slaves)

with perfect town planning,

the Romans constructed

world-famous aqueducts.

Today, Roman Aqueducts can still be found. In countries such as France,

Spain and Germany which were once under the rule of the Roman Empire,

there are aqueducts serving as a testimony to the glorious Roman history.

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4) Entertainment and Living

A) The Colosseum

The Colosseum is a landmark of Roman arch structure, symbolising the

cruelty of fights and heroic scenes of gladiators in ancient Roman times. The

four-tier Colosseum is supported by limestone and Roman’s own invention -

concrete. This spacious structure could accommodate eighty thousand

audiences and has a total of eighty entrances and exits. Velarium could be

extended to shelter the audience from rain and sunshine. The arena has

multiple uses: water could be poured into it to stage a naumachia, or it

could be loaded with sand on occasions of gladiator fighting, chariots racing,

drama performances or festivals. Ancient Romans were class-conscious. The

lowest tier was for the king and high-ranking officials. The second tier was

for the middle class. While the third tier was for slaves and foreigners, the

highest level was for women and poor people. Wild beasts were kept at the

basement and an underground lift was installed to bring the animals into

the arena.

B) Roman Tablet (Tabula Rasa)

Papyrus was expensive in ancient time so the

Romans used a wax tablet instead. Wax was

poured onto a wooden framework and a sharp

metal pen was used for writing. The tablet

could be reused by scraping the wax with the

warmed flat end of the pen. Ancient Romans

were really smart on living.

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Online Resources

Julius Caesar:

http://www.vroma.org/~bmcmanus/caesar.html

http://www.pbs.org/empires/romans/empire/julius_caesar.html

http://www.kidspast.com/world-history/0085-julius-caesar.php

http://rome.mrdonn.org/caesar.html

Roman Empire:

http://www.roman-empire.net/

http://www.roman-empire.net/children/index.html

http://www.pbs.org/empires/romans/

http://www.unrv.com/empire.php

http://library.thinkquest.org/22866/English/FRAME.HTML

http://www.metmuseum.org/toah/hd/roem/hd_roem.htm

http://www.bbc.co.uk/schools/primaryhistory/romans/

http://www.rome.mrdonn.org/