The Stone Age Observatory.
It is well known that a lot of ancient constructions are oriented according to the cardinal points but not long ago scientists turned upon archeological monuments. One of their function was to observe the celestial bodies. The celestial bodies are studied by archeoastronomy - a new branch of science lying between astronomy and archeology. The ancient monuments studied by archeoastronomy had been used for observing the sun and the moon. These ancient observatory were the constructions of "horizontal astronomy", that is they marked the points of Sunrise and Sunset (they could not measure the hight of the celesting body over the horizon). Such constructions are noticed everywhere - in Europe, in Asia, in America and Africa.
Archeologists found a lot of stone constructions of such type. They are called megalits (from Greek "megas" - "great"; "litos" - "stone"). These constructions had been built more earlier then the first Indo-Europeans appeared in Europe and we can say that the builders of those megalits were the antient celtics. So in a stone age there lived some trades, related to each other, having the well developed culture. Those trades are called sometimes the megalits builders.
The Great Stonehang.
None of the giant ancient constructions were given so much attention as to famous and mysterious Stonehang. It may be justly called one of the first monuments to the human thought.
In the Middle Ages it was considered that Stonehang (from ancient English Stan Hangues - "Haning Stones") was set up by the King of celtic tribe of Britons in memory of battle against saxons. They say that Merlin - the greatest magician was setting it during one hight. But this is only a myth.
In 1771 John Smith the doctor carefully measured all the stones and came to a conclusion that Stonehang had been not only the Sun temple but even a calendar. He noted that there were 30 stones in one circle which was equel to the number of days in the Moon mouth. If multiplay it on 12 (the number of months) it becomes 360 corresponding to the number of days in the ancient Sun year.
Stonehang was a giant observatory built for observing the sun and the Moon moving. With help of it an important task was disolving that is detecting the day of summer solstice, when the sun arose above the Heel Stone celebrating the end of the year cycle.
The scientists turned to the thrilits' design (see picture). Through one of them the sun, arising in a day of a winter solstice, could be seen. Two thrilits were used for the Moon observation. In the days when the Moon crossed the ecliptic there appeared possibility of the Moon or the Sun eclipse. Stonehang was built to warn this "danger". Gerald Hockens, the scientist, showed that in the II-nd thousandyear B.C. the Moon and the Sun eclipses may occured then the winter Moon arose above the Heel Stone. Besides this, the Moon eclipses may occur also in autumn. During this time the point of moonrise coincided with the definite stone of external circle (this repeated every 18 years). After three circles it would be 56 years. But the figure 56 is just the number of "Orby holes" (Orby is the first investigator of Stonehang). Owing to these holes the more "dangerous" moments of the moon and the Sun approaching might be notified. According to Hockens the founders of Stonehang used six shifting stones to foresee the year and the season of eclipse.
It is interesting the name of the main stone of Stonehang. Orby called it a Heel Stone because he had seen a small hole in it looked like a heel trace. However the scientist might write from the natives words the name left from ancient Britons who called the stone "sunny" - (celtic word hoal - "the sun" - sounds like English "heel").