An Ancient Method of Finding and Extending Direction

Abstract

The ability of the ancient Egyptian surveyors to orient some of their monuments to the meridian with accuracy has long perplexed modern societies. Although generally their temples were not well placed, the pyramids, and especially the Great Pyramid, were oriented almost precisely to True Geographical North. To account for this, various methods have been proposed which range from pure chance to a precise star measuring system. I believe, however, the means used for orienting the pyramids was actually based on the movements of the sun. Many ancient cultures have made use of the sun's movements by measuring its shadows with an instrument called a gnomon, a pole placed vertically on the ground. Ancient pictographs show the Egyptians, too, made use of this instrument. With the gnomon and a notched device called a bay (once considered to be a means for sighting distant stars), they were able to read the shadows with precision. In addition, the direction found by this gnomon, although short, can be extended accurately by use of the Stretching of the Cord ceremony, a foundation-laying ritual. The state of ancient Egyptian technology indicates that the pyramid builders had access to only the most rudimentary devices. For example, the magnetic compass, which we take for granted, was unknown to them. Indeed, if they had been acquainted with its use, the magnitude of error would have been much greater, for the north magnetic pole, which the needle seeks, is not on the meridian as is the geographical pole but varies according to the place and the year the reading is taken. In addition, their knowledge of astronomy was at a very elementary level, their greatest astronomical achievement being the calendar.1 Whatever means were used by the ancient surveyors, the results are truly remarkable.