Wonders of World Engineering

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In various parts of the world there are outstanding examples of the skill of craftsmen thousands of years ago. The pyramids and obelisks of Egypt, the stone circles at Stonehenge and the mysterious statues of Easter Island are among the timeless monuments of bygone ages

THE STONE CIRCLES of Stonehenge were erected thousands of years ago

THE STONE CIRCLES of Stonehenge, on Salisbury Plain, Wiltshire, were erected thousands of years ago. The outer ring of stones has a diameter of 108 feet and consisted of thirty huge monoliths with lintels mortised to them. Sixteen uprights and five lintels remain. The white patches in the background mark the site of the stones of a now vanished outer circle. The inner circle of monoliths originated in South Wales; these stones were probably brought to Wiltshire by water as far as Amesbury.

THE great days of monumental engineering have long gone by, though in modern times many marvels of engineering have come into existence which may be fairly termed monuments — monuments of invention and industry, records of labour accomplished and difficulties overcome. The Forth Bridge and the Panama Canal, for example, constitute the finest possible monuments to the men who planned and built them. Such men can justly claim, in the words of Wren’s great epitaph at St. Paul’s Cathedral, London: Si monumentum, requiris, circumspice (“If you seek a monument, look about you”).

The watchword of modern engineering is public utility. Only in rare and exceptional instances is it associated with mere glorification. In the monuments of the past, however, such was often the sole motive which brought about the accomplishment of remarkable feats of engineering, successfully tackled with primitive appliances, and involving problems which, in many instances, would not prove easy to solve even to-day. Foremost among these is that colossal structure which, many centuries before the Christian era, was universally regarded as foremost among the Seven Wonders of the World — the Great Pyramid of Cheops, at El Giza (Gizeh). More than five thousand years old, it stands to-day, scarred and weather-beaten, but substantially unaltered. The ziggurat of Ur, in Iraq, probably similar to the famous Tower of Babel, is by no means as well preserved as the Great Pyramid. Incontestably the largest, most impressive and most famous monument ever raised by man, the Great Pyramid will probably endure for many thousands of years.

Egypt is the home of pyramids, though there are many, of a somewhat different type, in Yucatan, Mexico, the Far East and Polynesia. El Giza alone can show more than a dozen, and there are many others at Thebes, Abusir, Sakkara, Dahshur, in the El Faiyum and in Nubia. But only one other — the Pyramid of Khafra, also at El Giza — even approaches in size the Great Pyramid, which for age and interest is unrivalled. The Great Pyramid was built during the reign and at the order of Khufu, the second king of the fourth Egyptian dynasty (the “Cheops” of the historian Herodotus), and was intended to serve as Khufu’s tomb. Tradition records that the building of the pyramid occupied 100,000 men for thirty years. Modern research has suggested that the centre of this period cannot be far from 3400 B.C.

At first sight, paradoxically enough, the Great Pyramid appears quite small. Rising out of a sandy plain, it shows up, sharp and, clear-cut in the pure Egyptian air, while still many miles away. It must have measured, when completed, about 770 feet along each side of its square base, its apex rising 480 feet from the ground. At the present day, having been stripped of all but a small part of the smoothed stone casing which originally covered the layers of cyclopean masonry of which it is composed, it measures about 755 feet on each side, with a height to the apex of about 450 feet.

Apart from one or two comparatively small interior chambers and their connecting passages, the Great Pyramid is virtually a solid, built-up mass of masonry, formed of huge limestone blocks arranged in layers — similarly to the bricks in a wall — the stones of each layer overlying the joints of those in the layer below. The average thickness of the blocks in each layer is about 3 feet and their dimensions, which are not uniform, range up to 20 feet long and 6 feet wide. The total weight of stone in the huge structure exceeds 6,000,000 tons.

It must have been planned and built with an exactitude which, for its date, is nothing less than extraordinary. There seems little doubt that its builder intended to place its centre in exactly latitude 30° N. and came within a mile of doing so. By modern observations, it lies in approximately 29° 58' 51" N. The difference of about one minute is probably due to refraction, and its small amount is an eloquent tribute to the accuracy of the original (astronomical) observations. Again, the four sides of the enormous square base have been orientated to the four cardinal points — the true (not magnetic) north, south, east and west — with amazing accuracy.

The extreme error of orientation is about 4½ minutes of arc — in other words, the 770-feet square of the original base has each of its four corners within one foot of the theoretically correct position. The successive layers of the exposed masonry show virtually no divergence from a true horizontal level. The huge, unmortared stones composing those layers butt together as accurately as though they were machine-made bricks; and in the places where the smoothed outer casing of stone still remains it is difficult to force the blade of a knife between the components.

Although the building of the pyramid undoubtedly involved an amount of labour which, to modern eyes, borders on the incredible, the methods used may, at least, be surmised.

Presumably the base, on a granite outcrop about 150 feet above the surrounding sandy plain, was first cleared and levelled, and the position of the first layer of masonry was accurately laid off. Within the pyramid is a long, inclined shaft running downwards into the solid rock for a distance of 350 feet.

Its inclination (about 26° 30') points to the conclusion that its construction was the first step in the building of the pyramid, and that it was used for orientating the base by observations of what was then the Pole Star — the star Alpha Draconis (much brighter in those days than it is now), situated about 3° 30' from the North Pole of the heavens.

The enormous quantities of hewn stone required were probably transported by water from the various quarries along the Nile, and dragged on rollers from the river bank to the site at El Giza along a prepared causeway (whose building alone, by Herodotus’ account, occupied ten years). The bottom layer of blocks (770 feet square) once in position, those forming the next layer were probably hauled up on to its surface, either by manual labour or with the help of capstans, along inclined ramps. Then, still on their rollers, they were shifted horizontally to their assigned positions.

AFTER THOUSANDS OF YEARS the Great Pyramid of Cheops, at El Giza, Egypt, still stands in excellent preservation. It has lost the smooth stone casing which originally covered the layers of cyclopean masonry. It now measures 755 feet along each side and is about 450 feet high. Tradition records that it took 100,000 men thirty years to build it.

It is possible that the ramps were continued, spirally, round and round the pyramid as it rose, keeping pace with the layers. In this way the inclination of the ramps to the horizontal — and hence, within limits, the effort required to elevate each block — could have been kept down to any suitable amount. On the other hand, if adequate power were available — which, considering the huge numbers of men employed, is not unlikely — the stones may have been hauled bodily up ramps which left the ground in the centre of each of the four sides, and rose straight towards the apex of the pyramid at the same inclination as the sides themselves — about 51° 50' to the horizontal. As soon as the last comparatively tiny layer was in position at the apex, the ramps would be removed and the pyramid given its outer stone casing, the angles at the edges of the main layers being filled to present a smooth, unbroken exterior surface.

According to the geographer Strabo (c. 64 B.C.-A.D. 19), a small entrance, giving access to the interior chambers and closed by a delicately-poised, swinging block, was provided near the centre of the northern face. In the ninth century A.D., however, when the Caliph Al Mamoun determined to possess himself of the treasures which the Great Pyramid was rumoured to contain, his workmen completely failed to find any trace of an entrance, and were compelled to drive an exploratory tunnel, with enormous difficulty and at vast expense, right through the solid stonework. They managed, eventually, to blunder upon the ascending gallery leading to what is known as the King’s Chamber — which proved to be a small room whose walls, floor and ceiling were all composed of exquisitely polished red granite, and which contained nothing whatever except an empty, lidless sarcophagus.

Although dwarfed by comparison with the pyramids of El Giza, the obelisks of ancient Egypt represent an even higher standard of engineering achievement. They are much larger and heavier than any of the stones composing the Great Pyramid, and their proportions — square in section, slightly tapering, and ten times as long as their width at the thicker end — make them fragile. The transport and re-erection of a few in modern times have served to indicate the severe difficulties which their original erectors successfully overcame.

Shaped from the Living Rock

The largest of all the Egyptian obelisks was never erected. It lies at Aswan, in a long-abandoned quarry which was carefully excavated and examined in 1922. The obelisk, which is 143 feet long and weighs about 1,000 tons, was found to have been completely shaped on the top and sides, but never undercut, remaining united with the living rock. The cause of its abandonment was also discovered — a flaw near the centre, indicating that it could not possibly have been got out whole. So far as could be gathered, neither chisels nor wedges had been used to shape and smooth it, this work being entirely performed by dressing tools composed of balls of hard rock, weighing some 9 lb. to 15 lb.

The largest obelisk — 97 ft. 6 in. high — still standing in Egypt is that of Hatshepsut, at Karnak. It bears an inscription stating that, with its companion (the obelisk of Tethmosis I), it was made and erected in seven months. In the same way as most of the larger Egyptian obelisks, it is of pink syenite.

It is uncertain how the makers of these huge stone needles went about the work of erecting them. In almost every instance the pedestal has a deep notch across it, fairly close to one edge. This may have been used to receive one edge of the obelisk’s base, and so act as a pivot round which the obelisk could be levered upright. This was the method by which the tallest monolithic obelisk now standing (105 ft. 6 in. High — in the piazza of St. John Lateran, Rome) was re-erected in 1552.

Originally erected at Heliopolis by Thothmes III in the fifteenth century B.C., it was transported to Rome — many of the Egyptian obelisks went overseas in Roman times — by Constantine the Great, and set up in the Circus Maximus, being ultimately transported to its present site at the instance of Pope Sixtus V.

During the last century three Egyptian obelisks have been transported to distant sites. The first to be moved was that which now stands in the Place de la Concorde, Paris. It was presented in 1830, while still standing at Luxor, to the French Government. Its removal to Paris occupied no less than six years all told, the date of its re-erection in the Place de la Concorde being October 25, 1836. The engineer in charge, M. Lebas, proceeded along strictly classical lines, using inclined causeways, capstans, forests of scaffolding and a small army of workmen.

The speed of the initial operations varied rather curiously. Lebas contrived to tilt the obelisk from the vertical through an angle of 60° in twenty-five minutes, but to lower it through the remaining 30° to the ground occupied eighteen days. Another month saw it hauled along 1,500 feet of causeway and embarked in a French frigate, whose bow, temporarily removed, was then replaced. The estimates of what her laden draught would be proved too optimistic; so she did not get down to Alexandria until January 1833. Bad weather caused further delay, and the obelisk was not disembarked at Paris until August 1834. It is 75 feet long and 8 feet square at the base; the weight is 225 tons.

A slightly smaller obelisk — now world-famous as Cleopatra’s Needle — had been offered by Egypt to Great Britain, as the Luxor specimen was to France, in 1830; but no official action followed, either then or later. In 1877, however, a private citizen, Professor Erasmus Wilson, came to the rescue and paid out of his own pocket the estimated cost of transporting it to England (£10,000). The work of removal and re-erection was entrusted to Mr. John Dixon, A.M.I.C.E.

Obelisk's Voyage of Adventure

Dixon had a slightly easier job to lace than his predecessor, Lebas. The obelisk — one of a pair removed from Heliopolis to Alexandria by the Emperor Augustus in 23 B.C. — was lying prostrate on the shore, its base, undermined by erosion, having given way about three centuries earlier. It was a little smaller, too, than the Luxor obelisk. Cleopatra’s Needle was 68 ft. 51 in. long and its rectangular base measured 7 ft. 10| in. by 7 ft. 5 in. Its weight was 186 tons. The undertaking, however, presented considerable difficulties, and the speed and certainty with which it was carried through reflect the greatest credit on its chief engineer.

Dixon designed a special craft — the Cleopatra, an iron cylinder with pointed bow and stern — to carry the obelisk. This was jacked up and the Cleopatra, shipped from England in sections, was built round it. The whole was then rolled down the shore and, after one false start (caused by a submerged rock puncturing the hull), successfully launched. The queer-shaped craft was then docked and fitted with a small deckhouse for her crew. She left for England in tow of the Olga on September 21, 1877.

The heavy-laden little Cleopatra proved a difficult tow. In spite of extra-deep bilge keels, she rolled excessively. Even in a flat calm the best helmsman could not keep her from yawing drunkenly to either side of her course. October 14 found the two ships half-way across the Bay of Biscay, vainly struggling to make headway against a heavy gale. After several hours’ pounding, the Cleopatra’s ballast shifted and she all but turned turtle. The six hands on board, unable to right her, were in imminent danger; but the Olga, after having lost a boat and the boat’s crew of volunteers, managed to take the Cleopatra’s men off at the second attempt. The tow was cut and the Cleopatra was abandoned to her fate.

CLEOPATRA’S NEEDLE now stands on the Victoria Embankment, London. It is an obelisk moved from Alexandria in Egypt, in 1877-78. It weighs 186 tons and is 68 ft. 5½ in. high. The rectangular base measures 7 ft. 10½ in. by 7 ft. 5 in.

Two months later she turned up, safe and sound, at Ferrol, in Spain, having been found drifting by the Glasgow steamer Fitzmaurice and brought in. Ultimately, towed by the Anglia, she reached the Thames on January 21, 1878. Her precious freight once safely alongside the Embankment, Dixon erected a 50-feet timber staging straddling the granite plinth, and encased the middle third of the “Needle” in a close-fitting wrought-iron jacket provided with trunnions. These trunnions turned on knife-edges, and so accurately was their position adjusted that the whole great mass could be pivoted round them by a single-handed push.

On September 12,1878, the “Needle” was jacked up, horizontally, until its centre was high enough, swung into a vertical position and gently lowered until it rested squarely and permanently on its plinth. A cavity in the core of the plinth had previously been filled with an extremely miscellaneous deposit of souvenir articles running into hundreds of items, and including such things as a complete set of British current coins, a cheap razor, a feeding bottle, Bradshaw’s Railway Guide, photographs of a dozen contemporary beauties, and copies of Engineering and of Whitaker’s Almanack.

The engineering operations had gone without a serious hitch from start to finish, and Dixon had the satisfaction of reflecting that he had designed and built the Cleopatra, embarked the “Needle”, transported it to England and re-erected it on the Embankment,

all in less time than it had taken Lebas to shift the Luxor obelisk from one side of the Place de la Concorde to the other.

Two years later the remaining obelisk of the pair at Alexandria was transported to the United States at the expense of W. H. Vanderbilt. The American engineers used a curious combination of ancient and modern methods — Dixon’s hydraulic jacks and knife-edge trunnions, Lebas’ ship of ordinary form with a special entry-port, and the timber raft on which the Emperor Caligula had transported obelisks in Roman days.

Statue Weighing 1,200 Tons

In lowering their “Needle” to the ground at Alexandria the engineers nearly cracked it in two, the trunnions not having been properly centred; but after that the work proceeded without difficulty. The obelisk was erected in Central Park, New York, in January 1881.

American ingenuity has produced also one or two curiosities of monumental engineering in the shape of built-up obelisks. The first of these was the Bunker’s Hill Obelisk, whose foundation stone was laid on June 17, 1825 (the fiftieth anniversary of the battle), in the presence of the famous French patriot Lafayette. It is 30 feet square at the base and 220 feet high. A similar structure, but much larger, is the Washington Monument, built at Washington, D.C., intermittently over a period of years and inaugurated on February 21, 1885. It is 555 feet high and 55 feet square at the base, and weighs, with its foundations, over 81,000 tons. For four years — until the erection of the Eiffel Tower in 1889 — it was the tallest structure in the world.

WASHINGTON MONUMENT is 555 feet high and 55 feet square at the base. Built of white Maryland marble, it is probably the tallest structure that can be built with stone. It weighs more than 81,000 tons, and was inaugurated at Washington, D.C., on February 21, 1885.

Of all the engineering marvels accomplished by the ancient Egyptians, perhaps the most wonderful is the erection of the twin colossal statues of Amenhotep near Thebes. Even in their present mutilated and defaced condition these two huge, seated, stone figures are a most impressive sight. The eastern figure came to be known as Memnon (the fabled son of Eos, the Dawn). It is the celebrated “vocal statue” and has had its upper half destroyed and rebuilt; but the western statue has remained substantially unaltered, although much defaced by weathering, since it was erected about 1500 B.C. It is plainly a monolith, a single block of stone, weighing approximately 1,200 tons. The sculptor has left it on record that these huge single masses of stone were hewn out hundreds of miles from Thebes (probably at the Toora quarries, near Cairo), transported up the Nile on barges, and then erected — all with the crudest of appliances.

All that can be conjectured of the methods most probably used is that the two gigantic blocks were transported to and from the river on stone rollers running over paved causeways; that advantage was taken of the annual rising and sinking of the Nile to get them waterborne in, or between the barges; and that they were erected by being hauled up a stone ramp with a gradual rise, ending in a perpendicular face, some 25 feet high, immediately overlooking the site. Each monolith was probably cautiously tilted over this face until it was upright, the ramp being afterwards pulled down and removed.

Although unexampled, and not far from incredible, the legend attaching to the eastern colossus — that, for a period of about two centuries (20 B.C.-A.D. 196) it saluted the rising sun by emitting a musical sound — is well authenticated. Evidence of the fact is to be found in the writings of several contemporary writers.

The sound was not heard every morning; but, when it did occur, this was always at or about the time of sunrise. It varied in note and intensity. Most of its hearers describe it as resembling the sudden breaking of a harp-string. It seems to have been a purely natural phenomenon. It first attracted attention not long after the upper half of the eastern statue had been thrown down by an earthquake (27 B.C.), which also damaged the western statue less seriously. The lower half of the eastern figure remained standing, but divided by a huge vertical crack running from waist to feet.

The statue faced south-east, so that its left side would be warmed by the sun’s rays, and thus would expand slightly, sooner than the right. It is at least possible that the sound was due to the unequal expansion of the two — causing one to move, suddenly and microscopically, in relation to the other. This is borne out by the fact that when the upper half of the statue was rebuilt in layers — probably by command of the Emperor Septimius Severus, early in the third century — and the halves of the lower portion, compelled to support this great additional weight, no longer had free play against each other, the mysterious sound was never heard again.

COLOSSAL STATUES of the ancient Egyptian king Amenhotep, built near Thebes about 1500 B.C. The figure on .he right came to be known as the statue of Memnon, the fabled son of Eos, the Dawn. For about two centuries (20 B.C.-A.D. 196) the statue emitted a musical sound at dawn. The sound was possibly due to the uneven expansion of parts of the figure as the heat of the sun increased. Each statue—65 feet high— was originally carved from a single block of stone.

The famous stone circles of Stonehenge, on Salisbury Plain, Wiltshire, represent a considerable feat of engineering, particularly since it has been shown that, although the great stones forming the outer circle were obtained locally, those of the smaller inner circle — blocks shaped into stone pillars standing 8 feet and more out of the ground — were brought all the way from South Wales, being transported by water as far as Amesbury. Moreover, all the work of dressing and shaping the stones was done with stone tools. The makers of Stonehenge, working probably about 1700 B.C., had no knowledge of iron, and it is doubtful whether they even knew bronze.

Excavation has revealed the method used for erecting the largest two of the central stones, rising about 21 feet above ground level. The stone was first shaped while lying horizontally. A slanting trench was then dug through the chalk of the site to a predetermined depth; the trench ended in a perpendicular face against which the side of the stone could rest when it was uprighted. This face having been used as a fulcrum, the great boulder was then levered and dragged upright inch by inch, being hauled from in front and pushed' upwards by wedges and struts from behind. Once it was upright, the pit was filled in with chalk and rubble. The smaller pillars of the two concentric rings were probably raised in the same way, and the transverse blocks (the “imposts”, or lintels) across their tops were hauled into place up inclined ramps of beaten earth and chalk.

Eighteenth-century Russia was the scene of a little-known engineering feat which recalls the erection of the Theban colossi. Soon after her accession in 1762, the Empress Catherine II of Russia commissioned (from the sculptor Falconet) a gigantic equestrian statue of Peter the Great, to be erected in St. Petersburg (now Leningrad). It was decided that, if possible, the pedestal should consist of a single granite block. After prolonged search, a suitable block was reported from Finland. Resembling an enormous grand piano in shape, it was approximately 42 feet long, 27 feet in maximum breadth and 21 feet high. It weighed, in the rough, some 1,500 tons. The problem of transporting it was made no easier by the fact that it lay half-buried in a marsh.

Catherine offered a large reward to any one who, with all the resources of the Russian Empire at his disposal, could contrive to remove the rock, as it stood, to St. Petersburg. The formidable character of the undertaking and, equally, of the Empress, seems to have, daunted the Russian engineers, for the reward was won by a foreigner, Marinos Carburis, a Greek from Kephalonia. He published an illustrated account of his proceedings in 1772.

Giant Pedestal on Ball Bearings

Carburis began work at the site early in winter, when the marsh was virtually frozen solid. With great labour, a pit was dug down to the level of the great rock’s base, and an immensely strong wooden frame, recessed for a large number of screw-jacks, was built alongside it. Then, using ship’s masts (hauled on by tackles) as levers, Carburis managed to tip the rock over so that its narrowest edge rested squarely on the frame.

This was next jacked up, and two trackways inserted under it. These trackways consisted of wooden V-shaped troughs, faced with iron, in which lay a number of cannon balls. Similar V-shaped recesses had been formed on the underside of the frame; and when this had been lowered the whole gigantic mass was supported, virtually, on ball bearings. A second pair of trackways, bolted to the first, was laid out in the required direction and well-manned capstans, working by beat of drum, hauled the load from the first to the second. The first trackways were then unbolted, hauled up to the front and relaid. When it became necessary to change direction, Carburis jacked up the frame and lowered it on to a circular turntable (similarly resting on cannon balls) by which the rock could be turned to any required direction.

Travelling at a snail’s pace, the singular procession ultimately reached one of the many branches of the River Neva, whence the great rock could be transported by water to the capital. Here the element of farce entered into what was otherwise a serious and creditable performance. The Russian Admiralty had undertaken to build a barge which, with a draught not exceeding 8 feet (the maximum the Neva would allow), should be able to embark and transport the rock.

AN IRON CYLINDER was built round the obelisk, later known as Cleopatra’s Needle, which was lying flat on the shore at Alexandria. The cylinder having been completed, it was jacked up and rolled down into the sea.

Carburis found waiting for him a wooden barge 180 feet long, with a beam of 66 feet, flat-bottomed and wall-sided. To facilitate the embarkation, this barge was brought alongside the bank and scuttled, the rock being then hauled on to a wooden bed installed at the centre of its keel. The Admiralty representatives then politely informed Carburis that his share in the operations was over; they would pump out the barge and tow her to St. Petersburg.

Unfortunately, it had not crossed their minds that a long craft of light draught, excessively loaded at her centre and nowhere else, requires a great deal of girder-strength; otherwise, she will bend or break. After the barge had been pumped out, her bow and stern rose high above water, forming an inverted arch, while her middle remained immovably pinned, by the weight of the huge rock, to the bottom of the Neva. Meanwhile her seams opened widely, and the water came in almost as fast as the men could pump it out.

Crestfallen, the authorities requested Carburis to disembark the rock while they considered what to do — but he had other views. He demanded, and obtained, the full control of all the remaining operations. He rescuttled the barge, pinned her ends down with loads of stone, and, once the keel was flat again, kept it so by fitting struts, in the shape of a forest of great beams, from the ends of the barge and from intermediate points to the face of the rock, these struts being wedged and cross-braced. Having been pumped out, the barge rose, without deformation, to her designed draught, and was towed down the Neva without further difficulty. Once arrived at St. Petersburg, the rock was disembarked, and transported by the trackways to its site (September 30, 1769).

Easter Island, a tiny speck of land in the South Pacific Ocean, offers a problem of monumental engineering which, at present, is far from being solved. The island was discovered on Easter Day, 1722, by the Dutch circumnavigator Jacob Roggeveen, who found it measured only 13 miles by 8 miles.

Mystery of Easter Island

Roggeveen did not stay long, but he noticed, at various points of the coast, enormous stone idols, some 30 feet high, standing with their backs to the sea. Later explorers, such as Gonsalez, Cook and La Perouse, confirmed his account. In modern times a good deal of information about these strange figures (all of which have now been overthrown, either by accident or design) has become available. There is a small but typical specimen of them — the statue of Hoa-Haka-Nana-Ia — on the colonnade of the British Museum, London. With a headless companion, it was brought from Easter Island by H.M.S. Topaze in 1866.

Apart from the question of who erected these statues, and for what purpose, the methods used in transporting and erecting them are difficult to make out. The figures are to be found, here and there, all over the island; yet they all came from a volcanic crater at the eastern end. Here the quarries in which they were cut can be traced, and on the slopes inside and outside the crater a number of the images still remain. Some of them are upright, but buried to the chin or higher by the descending soil. Some are recumbent, and others only partly hewn out.

One of these statues is 66 feet long, but the largest of those transported and erected stood 36 feet only. The images are carved out of compressed lava ash, a material which is comparatively light and fragile; yet there is no trace of any road leading away from the quarries, and no indication whatever of flow they could have been transported, unbroken, for several miles.

According to the eighteenth-century explorers who visited the island, the figures stood erect, on stone platforms, at the various ahu, or ceremonial burying places, and many of them were surmounted by cylindrical stone crowns. These, in themselves, were bulky objects to transport and raise — cylinders of red volcanic tuff, 4 to 6 feet high and 6 to 9 feet in diameter. The faces of the statues all conform to a peculiar convention — grotesque and fantastic, yet strangely impressive. Nothing quite resembling them is known elsewhere in the Pacific and their origin, purpose and manner of transport and erection remain at present an unsolved mystery.

THE CYLINDER IN TOW. After the launch of the iron cylinder containing the obelisk known as Cleopatra’s Needle, it was towed to dock and fitted with a small deckhouse. Named the Cleopatra, the queer craft was towed away from Alexandria on September 21, 1877.

You can read more on “The Eiffel Tower”, “The World’s Greatest Aqueduct” and “World’s Highest Buildings” on this website.

You can read more on “The Voyage of the Cleopatra” in Shipping Wonders of the World

Monumental Engineering