formerly University of Missouri-Rolla
The Original Stonehenge
The original Stonehenge, which was built in three stages beginning about 2800 BC and ending about 110 BC, can be classified as one of the world's outstanding engineering projects. Stones weighing many tons were cut, shaped, transported great distances and raised and placed with extreme accuracy using only limited technology. The first phase was built by the Late Stone Age people, the second phase by the Beaker people and the third phase by the Wessex people during the Bronze age.

 

Stonehege consists of a series of circular rings of standing stone set in a pattern which relates them to important positions of the sun and moon. Of the two major stone rings, the outer ring is made up of sarsen stones (12 feet high and weighing 25 tons), each capped with a lintel so that there is a walkway around the monument. Within this circle a series of five trilithons, each consisting of two uprights (21-25 feet high and weighing 50 tons) and a capstone, were arranged in a horseshoe shape. The entire array is oriented so that the rising sun at the summer solstice can be observed through the central trilithon aligned with the "heel stone" outside the ring.

 

The "heel stone," one of the first large stones which the early builders erected at Stonehenge, was 2- feet long, eight feet wide, seven feet thick and weighted an estimated 35 tons. This stone appears entirely natural inshape and was not altered by chipping or scraping.

 

The ancients observed that when the full moon rose nearly diametrically opposite the sun at sunset, a lunar eclipse was very probable later in the evening. England's Stonehenge has a group of 56 post holes, known as Aubrey Holes, arranged in a circle 284 feet in diameter. It is believed that these holes at one time contained wooden posts for sighting moonrise and sunset positions.