ENGINEERING FEATS

Evening Star, Issue 19023, 19 August 1925, Page 12

ENGINEERING FEATS

TRACED TO DAWN OF CIVILISATION Engineering marvels of our own time have led many people to assume that the present epoch will remain eternally noteworthy for its engineering triumphs. This idea has given rise to the impression, accepted by many engineers, that engineering, particularly civil engineering, is quite modern, and is the youngest of the great professions. _ However, history shows that engineering activities and skill develop in every period of advancing civilisation and decline in periods of retrogression. There were great civil engineers more than 4,000 years b.c., who were competent to carry out works of any size needed. Even at the dawn of history in Asia we find the remains of great civil engineering geniuses. But in the Middle Ages, when the freedom of the intellect was restricted, wo find little engineering work was done, and that little was done' by architects. The revival of science following the restoration of civil progress alter .the Dark Ages stimulated the activities of engineers, and the development of their skill continued until the present time. The Eiffel Tower, American skyscrapers, the Suez and Panama Canals, New York Harbor bridges, the Now York City water supply, and many works of this character are ranked among the grandest constructions of modern civil engineers. Four thousand years before the dawn of the Christian era there wore civil engineers who carried out works of similar difficulty and magnitude. The Nile-Red Sea Canal was no less an undertaking than the Suez or Panama Canal. And there were a great many similar canals constructed in Upper Egypt, in Abyssinia, and in Mesopotamia that any modern engineer would bo proud of having constructed. The Romans were expert hydraulic engineers. Many of their great water systems are in operation to-day, having weathered all the storms of time. The City of Romo was furnished an extensive and most efficient water system by many wonderfully-built aqueducts. The Aqua Appia Aqueduct was ten miles in length. It was chiefly carried underground. But it crossed a valley on a splendid set of brick and concrete arches, the ruins of which may be seen standing almost intact' today. Roman engineers constructed similar aqueducts and water systems in Franco, England, Spain, and Africa. Warm water was supplied to Home from the volcanic springs of Tepula, eleven miles south-east of the city, near Monte Albaui, or the Alban Hills, by the Aqua Tepuia. This hot water was used for baths and for warming houses. No works of this character are operated in any largo modern city. The Aqua Julia and several smaller systems also carried warm water to Romo from the Alban Hills. Roman engineers employed pipes resembling modern ones for drawing household supplies of water from the public and municipal aqueducts. These pipes were made of lead, copper, terra cotta, concrete, or drilled stone or wood. Earthenware pipes were commonest in use. Siphons were most ingeniously used by ancient engineer for carrying water up or over hills. A drrrfn pipe system designed to carry water under a head of 345 ft has been found near Alatvi, Italy.

Tunnelling was a branch of engineering that appealed to Roman and Greek skill. The Greek engineer Eupalinus in 625 b.o. constructed a tunnel Bft x Bft and 4,300 ft in length to convey water into Athens. The rock was cut in tumjels by picks, chisels, wood wedges, and similar means. It was a common practice to heat the rock bywood fires and then spray cold water over it. The rock was splintered in this way, and was easily broken down bypicks and drills. Harbor works suited to the needs of the great commerce of the Romans, Greeks, and Egyptians were constructed in many ports. The harbor at Alexandria constructed for the Egyptian Government by Minoan engineers at the time of the building of the great pyramids has not been excelled by modern works.

The lever, inclined plane, the screwjack, pulley, and many similar appliances were used by early engineers in their large construction works. These were cruder mechanisms than wo use to-day; but we should remember that in early times the world moved slowly. Engineers employed large armies _ of men and allowed them plenty of time to move large weights. By these means they were able to move or transport for hundreds of miles huge monoliths like the obelisks or some of tho great slabs used in the construction of the pyramids. The movement of any large weight never deterred an ancient engineer when unlimited time and men were assigned to him. Steady, patient perseverance enabled him to overcome all obstacles and create the innumerable historical works remaining to-day as testimony to his engineering and architectural ability.

Antipater of Sidon was the Baedeker of antiquity. He published guide books for travellers, and in one of these ho pointed out seven wonderful engineering works that he suggested everyone should see. These have since been known as the seven wonders of the ■world. Enumerated in the order given by Antipater, these composed tho Pyramid of Khufu, the Walls of Babylon, tho Statue of Olympian Zeus, the Temple of Diana, the Tomb of King Mausolus, the Colossus of Rhodes, and the Pharos of Alexandria. Those were considered by the ancients as their finest engineering triumphs, and modern scientific research confirms their judgment. But it should be remembered thqt these were simplv outstanding instances amidst a multitude of magni-

'-■oi- ■ "d to the cn-■ ginooring and constructive skill of the scienuucally trained professional men of the ancient world. I The walls of Babylon were built by | Nebuchadnezzar, who said on one of the cylinders buried in them: “I com- ; pleted Imgur-Bel and Nimitti-Bcl, tho . great walls of Babylon. At the en- ■ trance of tho great gates I erected , strong bulls of bronze and terrible i serpents standing upright. My father i did that which no previous king had ! done. With mortar and . bricks he , built two moat walls about the city, and I, with mortar and bricks, built 1 a third great moat wall and joined it t and united it closely with _ the moat walls of my father. ■ I laid its foinida- ! tion deep to the water level; I raised the summit mountain high. I con- j structed a moat tvall of burped bricks ] about the west wall of Babylon. i

“ My father built the moat wall of the Arachtu canal securely with mortar and bricks. He built well the quays along the opposite shore of the Euphrates, but he did not finish all his work. I built the moat walls of the Arachtu canal and finished my father’s works. Everything was constructed solidly.”

The hanging gardens in Babylon were also great engineering works. These were built for Queen Amytis, daughter of, the King .of Media and wife of Nebuchadnezzar. They were meant to represent the Queen’s native hills. They were constructed of huge brick enclosures arranged one upon another in a terraced pyramidal design. The ascent from terrace to terrace was made by ornamental stairs. This whore pile was sustained _ by vast brick and cemented arches raised on other arches and strengthened by brick walls and columns. Large, flat stone slabs wore laid over the arches, bitumen cement was spread oyer these, and then two courses of bricks. A thick sheet of lead was then spread over these to make them water and moisture’ proof. Garden soil and mould were then spread over the load. The soil wav deep chough to support tho growth of large mimosa, larch, cedar, laurel, acacia, and pine trees, palms and. fruits.

Diana’s temple, at Ephesus, was a wonderful palace constructed of red granite, with white marble facings. The classic poets have made the beauty of this .fine building well known. _ Its engineering features have received little attention. But they were noteworthy. The temple occupied the site of three or four previous temples. It was one of the largest buildings of , its kind. The foundations and underground cellars wore most extensive. Tall pillars of composite orders were used to support a gallery all around the mam building. Extensive terraces formed the approaches to the main entrance. These were constructed of granite with while marble trimmings set in concrete in the modern style.. Standing before the foot of the main stairway, in the park, were lines of raised embankments carrying statues of famous people, the gods and mythological figures and symbols. The colossus of Rhodes, tho pharos at Alexandria, the Tower of the Romans at Alexandria, and many similar monuments were built to mark the celebration of groat national events. Tho pharos at Alexandria was a lighthouse built for Ptolemy P.hiladclphus by an engineer named Sostratns. It stood on a small island at the entrance to the harbor, and was a building like the Woolworth, in New York, but architectually much more imposing. Four hundred and fifty feet above the ground there was a gigantic lamp, and this was surmounted by a graceful tower.

1 Apollo walking to the hunt with bows, arrows, and bird traps, cast in bronze, formed the colossus of Rhodes, t Like the statue of Liberty, in New, York Harbor, it was a striking feature of tho harbor at Rhodes. The two groat legs of this mammoth bronze bestraddled tho harbor entrance. Every ship sailed under them. At night a large lantern and torch, held aloft above the head, served as a navigation guide. I Chi Hwaim-ti, tho Napoleon of China, was the greatest of the early builders of that empire. He constructed an extensive and magnificent palace in his capital, Hicnyang, and commanded his engineers to construct a great wall across China from tho sea ,to the deserts, where previously a I number of disconnected smaller dol’en- : sive walls had been constructed. Millions of forced laborers were engaged ' for ten years on the construction. This groat engineering work was completed in tho year 204 b.c., and was so well executed that it stands complete today and is one of tho marvels of the Oriental world.

I Prehistoric Americans, like the early I Asiatic peoples, were constructors of buildings, bridges, roads, canals, and temples on a grand scale. Tho remains of their splendid cities, now being explored by archaeologists, indicate that the Incas, of Peru, the Mayas and oilier lost American peoples were master builders and engineers. Tho moderns do not excel tho ancients in the construction of great and artistic public works. An examination of tho en- | gmecring works of antiquity clearly i shows that in all active centres of ; civilisation men have been found who ; were capable of carrying out perfectly ■ plans for public works of any size i under any given conditions. No modern engineer could do more.—Now York ‘ Herald Tribune.’