The Ancient Engineers, page 8
Other ancient kings played rough, too, but without quite such fiendish gusto. Most Egyptian and Babylonian kings preferred to boast of their justice, piety, and public works, rather than of their cruelties and atrocities.
There is, however, another side to the Assyrians. They were gifted and energetic inventors and engineers. Some of their inventions stemmed from their militarism. For, despite the harm that it does in other directions, war certainly stimulates technology.
Thus the Assyrians were the first to equip armies with weapons of iron (—VIII). Iron had been known for seven or eight centuries. According to tradition it was discovered by a tribe in Asia Minor, the Chalybes, but for several centuries it was too precious for mass armament.
The Assyrians also developed remarkable new wheeled war machines. The wheel had already been known for several thousand years; there is a picture of a chariot on a Mesopotamian vase that may have been painted before —4000. In the 1920s Sir Leonard Woolley excavated the grave of the Sumerian king, Abargi of Ur (about —2500). In the tomb Woolley found, along with the skeletons of sixty-five attendants slain to serve the king in the next world, the remains of two wagons.
Each wagon was drawn by three oxen, which had been killed with the attendants. Each wagon had four wheels, as did the war chariots shown on an inlaid panel found in the same tomb. As the horse had not yet been tamed, each chariot was drawn by a pair of onagers—that is, Asiatic asses. This animal, however, did not prove well suited to domestication. Hence the modern domestic ass is descended from the smaller, African species.
The wheels of these vehicles were solid, built up of two semicircles of wood fastened together. To protect the rim from wear, they probably had tires of leather straps, through which large-headed copper nails were driven. Much later, in Assyrian times, tires of copper or bronze came into use, and later still iron tires.
Historians of technology suppose that the wheel evolved from the roller and that the first wheels were rigidly fastened to the axle, which turned with them. This seems logical, although there is little real evidence. The revolving axle, however, had the disadvantage that both wheels, forming an integral part of the axle, had to turn at the same speed. Therefore, when the vehicle rounded a corner, one wheel was bound to skid or drag. By King Abargi's time, the axle was fixed to the vehicle and the wheels rotated loosely and independently on the axle.
In Abargi's four-wheeled wagons and chariots, both axles were rigidly fastened to the body. Neither axle was pivoted, as is the front axle of any modern wagon so that it can follow the team around corners. Therefore these vehicles had to be manhandled around turns. Moreover, as anybody who has pushed a baby carriage knows, a four-wheeled vehicle with fixed axles tends to zigzag.
To make a wagon turn easily as the draft animals draw it around a bend, the front axle must be pivoted on a king bolt. This improvement, however, took a long, long time—perhaps twenty or thirty centuries. In the days of the Persian Empire, a four-wheeled carriage called a harmanaxa came into use, it may possibly have had a pivoted front axle. But, even after this mechanism was known, four-wheeled vehicles long remained rare. The simpler two-wheeled carts and chariots were more commonly used throughout ancient times. A shortcoming of ancient four-wheelers was that, even after they had pivoted front axles, their front wheels were made as large as their rear ones. Therefore they could not turn sharply because, if they tried to do so, their front wheels scraped.against the sides of their bodies.
The Assyrians also exploited the wheel by inventing the belfry, or helepolis, or movable siege tower. Fierce fighters though the Assyrians were, climbing a scaling ladder was always a desperate business. There was an excellent chance that the defenders would either drop a heavy stone or beam on the attacker or push the ladder over backwards.
Therefore some clever Assyrian engineer fixed the ladder to a wooden framework, too heavy to be pushed over, and put wheels under the framework. As the defenders could still pepper the attackers with arrows and other missiles, the next step was to board up the sides and front. Untanned hides were nailed to the structure to keep it from being set afire. The resulting wheeled tower or belfry remained a standard siege engine for over 2,000 years, until cannon made lofty walls useless for defense.
A further Assyrian improvement was to combine the belfry with a battering ram. A small ram was simply a log carried by a number of men. But, for breaching the walls of a real city, something larger was needed. Hence a tree trunk was shod on one end with a mass of metal and hung by chains from the roof of a shed on wheels called a tortoise.
The fully developed Assyrian belfry had six wheels and a ram working through a hole in front. Over the forward part of the tortoise rose the tower, as high as the wall to be attacked. During the approach, archers on the tower tried to clear the wall of defenders so that the attackers could scale it in safety. In several lively bas-reliefs, the defenders shower the belfry with torches, while a man in the tower hastily puts the fires out by pouring water on them from a dipper.
Sometimes, instead of a ram, the belfry was equipped with a bore. This was like the ram except that it had a sharp spearlike head. In attacking a wall of soft mud brick, such a tool might be more useful than a ram.
The Assyrians also exploited a new military arm, horse cavalry. Around —2000 or earlier, on the great grassy plain that stretches from Poland to Turkestan, a wandering tribe of cattle-raising nomads tamed the most important of man's working animals. This was the horse, which then ran wild from the forests of Germany to the deserts of Mongolia.
This feat of domesticating the horse had momentous results. The horse tamers set out in their rattling chariots and easily conquered their neighbors. They imposed their language upon their subjects and intermarried with them. These mixed peoples set out in their turn and conquered more neighboring nations. Thus the horsemen spread their speech from Portugal to Bengal. The family of tongues derived from that of the original horsemen is called Indo-European. The horsemen who conquered Iran and India called themselves Arya, "noble ones." Therefore, the original conquerors and their descendants are sometimes called Indo-Europeans and sometimes Aryans.
However, there is no "Aryan race." Whatever the race of the first horsemen, it has long since disappeared by intermarriage and dilution. The words for certain plants and animals, common to widely separated Indo-European languages, suggest that the original point of dispersion was south of the Baltic Sea—that is, on the plains of Poland.
For over 2,000 years, waves of Aryan barbarians—Kassites, Hittites, Cimmerians, Scythians, Medes, Persians, Dorians, Thracians, Celts, Germans, and Sarmatians—washed over the more cultured lands to the east, south, and west of their northern homes. Sometimes they were driven back; sometimes they set up mighty empires.
Their horsemen both rode and drove horses. For fighting, they drove chariots. Although they rode to carry messages or to travel fast, they did not usually fight on horseback. For one thing, the early horses were not big enough to carry an armored man very far. For another, having no stirrups and being topheavy from the weight of their armor, the riders were in constant danger of falling off.
One Indo-European tribe, the Medes, settled in western Iran. Here, on the Nisaean Plain, they bred horses for size until the horses were as big as modern riding horses. These could bear a man even when wearing armor. For centuries the Medes, the Persians, and the other Iranians had the world's best cavalry, not only because they were skillful riders but also because they had the largest horses.
The kings of Assyria, however, soon copied the Medes. Again and again they sent marauding armies over the mountains into Media to capture some of the famous horses for their own breeding stock.
In the ancient world, the chariot was built in many sizes and shapes and was pulled by one to four horses, mules, or asses. The maximum load was limited by the fact that the animals were always harnessed abreast, never in tandem. Therefore the number that could be hitched to a given vehicle was restricted by the width of roads and gates. Thus, although four-horse chariots were sometimes used for war and racing, cars for ordinary transportation were usually drawn by one or two beasts.
The Persians and the ancient Britons fastened scythe blades to the hubs of their war chariots to mow down foot soldiers. The people of the south and east of the Mediterranean preferred a chariot high in front and open in back, while those to the north and west made chariots high in back and low in front, with a seat across the back. In later centuries, the open-rear chariot, in which the driver stood up, was preferred for fighting, (hunting, and racing, whereas the open-front chariot was preferred for pleasure riding and simple transportation.
As a chariot needed smooth ground to run on, its military use was limited. Once men had the fine Median riding horse, chariots became less effective than the- same number of men mounted on horses. After the time of Alexander the Great, chariots went out of use for fighting, albeit they were kept for private carriages, governmental mail carts, and racing vehicles.
In addition to developing engines of war and cavalry, the Assyrian kings found time for peaceful public works. When Sargon II invaded Armenia in —714, he saw an irrigation system not yet known in Mesopotamia. This system, also used in Iran, can be called either by the Arabic name qandt or the Persian kariz.
A qanat is a sloping tunnel that brings water from an underground source in a range of hills down to a dry plain at the foot of these hills. It has an advantage over an open-air aqueduct, in that less water is lost by evaporation on its way from the hill to the plain.
To build a qanat, a line of vertical shafts is dug along the course of the conduit, and the bottoms of these shafts are joined by a continuous tunnel. At various points, other shafts are dug at a slant from the surface to the tunnel, to allow men to go down to maintain the tunnel or to draw water. Finally, when the tunnel reaches its destination, the water is distributed into a system of irrigation channels.
Sargon admired the Armenian qanawat. Although he destroyed them, he brought the secret back to Assyria. In later centuries, qanat irrigation spread over the Near East as far as North Africa and is still used in many places.
Sargon's son Sennacherib18 proved less aggressive than most Assyrian kings, although he suppressed revolts just as fiercely. The most remarkable thing about Sennacherib was his technical bent.
Sennacherib's empire included not only Assyria proper (northern Iraq) but also Babylonia (central Iraq) and Chaldea (southern Iraq). It included Syria and Phoenicia as well. Palestine was usually tributary, and Assyria for a time ruled Egypt.
The Assyrian kings ruled most of this area through native kings whom they had conquered but left in power on condition that they pay tribute and furnish troops to the King of Kings. The Assyrian kings tried to govern Babylonia through such puppet kings, but the puppets often revolted. In the —690s, Sennacherib deposed one restless Babylonian king and put one of his own sons, Ashur-nadin-shum, in his place. The leaders of the anti-Assyrian faction fled south into the marshes of Chaldea,14 where they thought they would surely be safe.
However, they reckoned without Sennacherib's engineering genius. He called upon the tributary Phoenician cities, far to the west, for ships. The ships, built in sections, were hauled overland and assembled on the Euphrates. They sailed down the mighty river to Chaldea, where they helped to rout the anti-Assyrians.
But not for long. The Babylonians soon rose again and drove out Ashur-nadin-shum. When the wrathful Sennacherib recaptured Babylon in —689, he massacred the people and sacked and burned the world's greatest city. Not yet satisfied, he dug canals through the city, dammed the Euphrates, and sent the river coursing through these canals. He dumped the temples into the canals and made such a vast muddy morass of the whole area that, for a time, Babylon became a wilderness.
Later, Sennacherib had second thoughts and began to restore the city. His son Esarhaddon continued the work. After the fall of Assyria, Babylon again became the largest city in the world.
The old capital of Assyria had been Ashur on the Tigris, but some early Assyrian kings made Nineveh,15 farther up the Tigris, an alternate capital. Although Sargon II built a new capital still farther north,16 Sennacherib abandoned his father's city and adopted Nineveh for his home.
Here a huge wall, faced with stone and pierced by fifteen gates, surrounded the two mounds on which the temples and palaces stood. The rest of the area, an irregular quadrangle about one mile from east to west and three miles from north to south, was occupied not only by the dwellings of the common folk but also by public parks and the orchards of private citizens. For his private garden, where storks clattered and pet lions prowled, Sennacherib designed an improved swape, with a copper bucket and posts of timber instead of dried mud.
To water all his fine plantings, Sennacherib undertook a vast scheme of waterworks. He personally toured the countryside near Nineveh, striding over plains and toiling up mountains, to choose the sites for his constructions.
Ten miles north of Nineveh he dammed the river Tebitu,17 which descended from the north to flow through the middle of Nineveh and empty into the Tigris. From the reservoir thus created he brought a canal down to the city. Since the grade of the canal was less than that of the river, the canal water arrived at Nineveh high enough to be used for irrigation without hoisting.
To take care of the overflow during the high-water season in spring, Sennacherib installed, northeast of the city, a municipal canebrake, like those of Babylonian cities. He made this marsh into a game preserve, loosing deer, wild boar, and game birds to breed there.
In addition to planting reeds and timber trees, Sennacherib imported from India another novelty: the cotton tree. His inscription proudly announced that: "The mulberry and the cypress, the product of the orchards, and the reeds of the brakes which were in the swamp I cut down and used as desired, in the building of my royal palaces. The wool-bearing trees they sheared and wove the wool into garments."18
Sennacherib's first canal sufficed for several years. When the city outgrew it, the king dug another canal to the northwest, where it tapped another stream. He also built over a dozen small canals connected with the Tebitu River and a 12-mile tunnel to bring water to Arbela,19 a city east of Nineveh.
When these schemes, too, were outgrown, Sennacherib undertook his most ambitious project. He went more than thirty miles from Nineveh, to the watershed of the Atrush or Gomel River. Thence a canal was dug overland to the headwaters of the Tebitu, carrying new water downstream to Nineveh.
Where the canal crossed a tributary of the Atrush-Gomel, near modern Jerwan, Sennacherib built an aqueduct. This was a remarkable piece of construction for its time. It was made of cubes of stone, one cubit (20 inches) on a side. In the actual channel, a layer of concrete or mortar under the uppermost course of stone prevented leakage. The aqueduct crossed the stream on a 90-foot bridge of five pointed corbelled arches, over 30 feet high.
Sennacherib prided himself on completing this canal and aqueduct in a year and a quarter. As work neared completion, he sent two priests to the upper end of the canal to perform the proper religious rites at the opening.
Before the ceremony, however, a minor mishap occurred. The sluice gate at the upper end of the canal gave way, and the water of the Atrush-Gomel poured down the channel without awaiting the king's command.
Sennacherib at once looked into the occult meaning of this event and decided that it was a good omen. The very gods, he believed, were so impatient to see the canal in use that they had caused the breach in the sluice gate.
So King Sennacherib went to the head of the canal, inspected the damage, gave orders for its repair, and sacrificed oxen and sheep to the gods. "Those men," he wrote, "who had dug that canal I clothed with linen and brightly colored woolen garments. Golden rings, daggers of gold I put upon them."20
This was no doubt a delightful surprise to the engineers and workmen, who had probably been shaking in their sandals ever since the mishap for fear that the Great King would order all their heads chopped off. He was, indeed, quite capable of it.
In —681, Sennacherib's sons conspired against him. The great engineer-king was lured into a temple in Nineveh and beaten to death with statuettes of the gods. One son, the grimly able Esarhaddon, succeeded Sennacherib and conquered Egypt. He it was who modestly began an inscription:
"I am powerful, I am omnipotent, I am a hero, I am gigantic, I am colossal!"21
After Esarhaddon came the melancholy Ashurbanipal, patron of arts and letters, under whom the empire reached its peak. Thereafter it swiftly declined as more and more of the subject peoples revolted and nomadic barbarians, the Cimmerians and Scythians, swept down from the north.
In —612, an alliance of Scythians, Medes, and Babylonians conquered Assyria. In assailing Nineveh, the Medes took advantage of a flood on the Tigris to mount battering rams on rafts. The allies captured the capital and blotted it out. A ferocious yell of triumph went up from the Assyrians' victims:
"Woe to the bloody city! . . . Nineveh is laid waste: who will bemoan her? . . . Thy shepherds slumber, O king of Assyria: thy nobles shall dwell in the dust: thy people is scattered upon the mountains, and no man gathereth them."22
Two centuries later, when Xenophon's ten thousand Greek mercenaries passed that way, Nineveh lay in ruins, and the memory of the scourge of Assyria was already fading from the minds of men.
At the time of Assyria's fall, a Chaldean adventurer named Nabo-polassar23 had seized the rule of Babylonia. Under him and his son, the second Nebuchadrezzar,24 the dynasty ruled much the same area as the former Assyrian Empire. This new empire is sometimes called the Neo-Babylonian Empire, because its capital was at Babylon, and sometimes the Chaldean Empire, because of the nationality of its ruling house.
