ANCIENT TOOLS

Greymouth Evening Star, 7 September 1939, Page 14

ANCIENT TOOLS

OUR INGENIOUS ANCESTORS. We engineers are inclined to indulge in much back-patting and self-con-gratulation, writes E. H. Hull in the “General Electric Review.” And not without good reason; but lest we become too smug let us make a hasty review of historians’ accounts of the engineering knowledge and accomplishments of ancient peoples. The more advanced races developed out of the stone age in prehistoric times. They used copper and bronze implement before written history, "hardening these soft metals by hammering. By about 1000 B.C. iron was replacing bronze for many uses. Smelting of metals was successfully practised, as well as the metal forming process of forging and casting With these materials, hand tools for all trades were made in numbers and variations rivalling the present-day list. In certain instances the ancient tools show a more refined design than our modern examples. ' For rock-cutting, the Egyptians employed copper saws set with corundum teeth capable of working in slabs of rock over seven feet thick. Core drills set with jewel stones for drilling rock could turn out work which has been judged the quality of that done by our modern reinvention, the diamond core drill

The size of the Great Pyramid built in 4700 B.C. is awe-inspiring; but a more astonishing feature is the. accuracy with which it was laid out and constructed, and which it has maintained. For instance, its sides have to-day a mean error of only seven parts in 100,000, which is but one-third of that which may be tolerated in a carefully machined part of a modern automobile.

An examination of the chambers in this pyramid shows that many of the seams between blocks of stone are nearly invisible, and that there are no signs of settlement cracks . or flaws. One wonders whether any of our modern structures will survive 6600 years in as perfect condition By 200 B.C. the Greeks had quite well developed plane and some solid geometry, knew the laws of levers and of centre of gravity, and something was known of relative density and hydrostatic pressure. In fact, until quite recently, plane geometry wias called Euclid, atfer the Greek scholar. Physics books now name the law of buoyancy after its Greek discoverer Archimedes. It was Archimedes who first determined to within one part in 10,000 the ratio of the circumference of a circle to its diameter. The Greeks also had some understanding of the arithmetical relations o" musical tones and the laws of light reflection .... When necessary, the Greek schclais could do outstanding engineering work, Archimedes was drafted for the defence of his native Syracuse against the Roman fleet and armies. . . . At the end of the pre-Christian era more attention was paid to practical devices containing the so-called modern machine elements such as wedges, jack-screws, pulleys, windlasses, levers, toothed gearing, etc. Compressed air and hydraulic devices "cree pumps, siphons, and pipe were known also. Hero or Heron, an Alexandrian engineer, described several useful machines, among them a hodometer similar to our bicycle odometers. Hero’s device, when mounted on a wagon, converted the revolutions of the wagon wheels, through suitable step-down worm gearing, to distance travelled, and showed this distance on a calibrated dial. For use as a taximeter, metal balls were arranged to be dropped by the machine into a resonant container, thus marking with a suitable noise the completion of each unit distance of travel ....

Hero’s surveying instrument, the dioptra, contained all the essential movements of the modern transit and included a long-base water level for accurate levelling. The familiar surveyors’ staff with movable sighting disc was used in its present, form. On the water the ancients got around quite well. About 600 B.C. the Phoenicians circumnavigated Africa. Later there was a canal from the Nile to the Gulf of Suez serving the same purpose as the present Suez Canal. . . . Ingenious and modern-sounding as many of these early devices are. they differ from our modern engineering projects in that they take no account of power. The ancients employed cheap and easily available slave labour. While this system was all right for the ruling classes, for the slaves themselves it meant untold labour and suffering. What have we done that the ancients did not do? We have extended, developed, and applied scientific and engineering knowledge in the directions that lead to social advancement for all. And the progress we have made gives us reason for pride even greater than that we take in our technical ingenuity.