The latest excavations (1902) prove Stonehenge to be a Neolithic erection. No metal was found, but quantities of flint implements, broken in the arduous task of dressing the great Sarsen monoliths. The process seems to have been that still used for granite, viz. to cut parallel channels on the rough surface, and then break and rub down the ridges between. This was done by the use of conical lumps of Sarsen stone, weighing from 20 to 60 lbs., several of which were discovered bearing traces of usage, both in pounding and rubbing. The monoliths examined were found to be thus tooled accurately down to the very bottom, 8 or 9 feet below ground. At Avebury the stones are not dressed.
Sarsen is the same word as Saracen, which in mediaeval English simply means foreign (though originally derived from the Arabic sharq = Eastern). Whence the stones came is still disputed. They may have been boulders deposited in the district by the ice-drift of the Glacial Epoch.
Professor Rhys assigns 600 B.C. as the approximate date of the first Gadhelic arrivals, and 200 B.C. as that of the first Brythonic.
Whether or no this word is (as some authorities hold) derived from the Welsh Prutinach (=Picts) rather than from the Brythons, it must have reached Aristotle through Brythonic channels, for the Gadhelic form is Cruitanach.