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WE should not be surprised that native Britons
succumbed to the Roman military invasion and were later seduced by their
way of life: the Romans were way ahead of their time.
The Romans invaded Britain in the spring of ad 43,
landing at Richborough in Kent and marching rapidly to take the
stronghold at what is now Colchester. The invasion was quickly
successful, partly because the Roman army was highly disciplined and had
an effective logistical infrastructure, but also because they could draw
on technology that was hundreds of years ahead of what was available in
Britain.
They introduced to this country not only straight
roads, elegant baths and flushing lavatories, but also rectangular
houses, apples, pears, carrots, turnips, three-course meals and even
hamburgers. The bars in Londinium and other Roman towns sold not only
hot breads, pastries and pies, but also fried patties of ground beef,
salt, pine kernels and a slurp of wine, eaten with bread - clearly a
precursor of the Big Mac.
Even today we drive on a number of Roman roads - the
A68 near Corbridge, Northumberland, the A2 in Kent, and so on - that
were built to get troops quickly around the country. They have been
resurfaced many times since the legions last marched on them, but tens
of miles of foundations and agger - the bank on which the road was laid
- have survived 2,000 years of wear and tear - a remarkable fact
considering that they now carry vehicles many times heavier than
anything the Romans rolled over them.
Better roads were not built until Thomas Telford and
John Loudon MacAdam came along in the early 19th century, so you could
argue that the Roman engineers were 1,800 years ahead of their time.
The most obvious thing about Roman roads is that they
are straight, but making a straight road is not difficult; what really
impresses me is their surveying.
When they decided to build a road from London to
Chichester, the Romans set off in exactly the right direction, even
though they apparently did not use map or compass. Instead, they used a
lovely piece of low technology called the groma, a stake stuck in the
ground with a horizontal frame in the shape of a cross on top and
plumb-lines hung from each arm. This allowed the surveyor to adjust a
beacon until it was precisely in line with beacons on either side. By
doing this all along the prospective road, they were able to mark out
the exact line they needed.
Once they had built their road network, the Romans used
it as a sort of grid to help calculate the size of farms and other land
holdings, in order to levy appropriate taxes. To measure the distances
from A to B, they first used pacers, soldiers trained to march with a
standard pace and to count their paces. The standard pace - left, right
- was about 4ft or 1.2 metres, and the Roman mile was mille passuum (a
thousand paces) which is about 0.8 miles or 1.2 km. They erected massive
milestones to record the intervals.
Later they built odometers, described by Vitruvius, in
order to measure the distances automatically and more precisely. Rather
than just being a dial on the dashboard, the Roman odometer was a
chariot in its own right, with wheels 4ft in diameter that turned
exactly 400 times in one mile. Each revolution, a pin on the axle
engaged with a giant 400-tooth cogwheel, therefore turning it once in
exactly one mile. At this point another gear meshed, and caused a pebble
(called a calculus) to drop into a box. So at the end of a journey, the
number of miles travelled was given directly by the number of pebbles in
the box.
This seems to have been rather more effective than the
device Sir Joseph Banks fitted to the carriage he designed some 1,700
years later, as described by one of his friends: "The vehicle
boasted a hippopedometer by which a traveller might ascertain the
precise rate at which he was going.
"This broke, in the first 10 miles of our journey:
whereat the philosopher to whom it belonged was the only person who lost
his philosophy."
The Romans also had an answer to flooding in mines,
which has been a problem ever since miners had enough technology to
tunnel deep into the earth. In 1712, Thomas Newcomen, a Dartmouth
ironmonger, built a large steam engine to pump the water from a coal
mine in the West Midlands. This was arguably the greatest ever step
forward in technology, for it provided portable power for the first
time, and hundreds of Newcomen engines were built in the next 50 years
before James Watt boosted their efficiency and versatility.
But the Romans had been pumping water out of mines
hundreds of years earlier. In the gold mines at Dolaucothi in south-west
Wales they installed water wheels some four metres in diameter; each was
powered by a slave walking up the outside, like a treadmill, and each
minute raised some 80 litres of water - half a bathful - about three
metres. A stack of such wheels, one above the other, pumped the water
clear out of the mine, from deep underground. As I discovered, driving
one of these water-wheels was both exhilarating and exhausting.
The Roman army needed clever signalling systems, for
example to get messages back from the front line at Hadrian's Wall to
Vindolanda and other forts a few miles south.
They had at least two simple code systems using flags
by day and flaming torches by night, and these were probably as good as
the celebrated telegraph invented by the Frenchman Claude Chappe in the
1790s.
Some of the technological ideas that the Romans dreamed
up were truly extraordinary.
Towards the end of the fourth century ad, an unknown
writer, alarmed that the mighty empire seemed to be crumbling, wrote a
long letter to the emperors (there were two at the time) suggesting a
number of devices that he thought would help revival. Some of these
suggestions were fairly sensible - methods of saving money on the army,
and a huge ox-powered paddle-ship that he claimed would be the fastest
thing on the sea.
However, he went over the top when he described his
idea of a portable inflatable bridge, which he said no modern army
should be without in case they had to get over unexpected rivers or
swamps.
Animal skins, carried on carts, were to be inflated
with bellows and lashed together to create a sort of giant lilo on which
the soldiers could cross dry-shod.
We decided to build one of these inflatable bridges,
though instead of animal skins we used floppy plastic bottles, and we
lashed them together with gaffer tape. After many hours of struggling, I
was just able to walk on the bridge across a modest river.
I could hardly imagine an entire legion marching across
with all their armour. However, the idea was not so daft, for today the
fire brigade use just such an inflatable bridge to rescue people who
have fallen through the ice, and to get across swampy ground, so perhaps
this dreaming Roman really was 1,600 years ahead of his time.
When they first arrived, weapons and armour provided
the leading edge of the new technology. Roman metal-workers were highly
skilled; their swords were probably harder and sharper than those of the
defending Britons, and their throwing spears were made with soft metal
shafts that bent on impact, so preventing the enemy throwing them back.
The Romans had several artillery weapons, including the
stone-throwing onager, named after the wild ass, perhaps because of its
kick, and the fearsome ballista, like a heavy crossbow on a stand. This
could shoot a 500g iron-tipped bolt 200 or 300 metres with deadly
accuracy.
There is even a description of a repeating ballista. We
built one of these and found that it could fire a bolt every five
seconds, which would have been devastating to an enemy armed with simple
bows and arrows.
The weapon may never have been developed because it was
too precise, and would have killed the same man several times, but the
technique has been revived in machines that throw tennis and cricket
balls at brave defenders, with much the same lethal velocity of 50
metres per second.
However, today's manufacturers have cunningly designed
the machines so that the balls swerve, for like politicians, they make
every delivery with spin.
Daily Telegraph, November 2000
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