How came they in their present position? In one sense they never came at all; for they existed on the surface of the chalk from the time it rose from the bottom of the sea to its present position. They are, in fact, the remains of a great sheet of fine sand and gravel cemented together by silex, which formerly overlay the chalk downs, the other parts of which have been dissolved and worn by wind and rain until only the harder cores or kernels survive to tell the tale. And the proof of this is not far to seek. The chalk of the London Basin is still capped by layers of such sandstone, as may be seen at Purfleet in Essex. The titanic sheep, or Grey Wethers, therefore, are merely a small residue of that widespread sandy deposit which once covered the whole of the south of England with its inhospitable sheet, and of which larger patches remain to-day in Surrey, Hampshire, and the Isle of Wight. But though the hand of Time and the buffets of the weather have been heavy on the Sarsens, the hand of man has likewise borne its share. In a district like the Plain, devoid of building material other than flint, these stones have attracted the unwelcome attention of the farmers. Walls, gateposts, and paving-stones have accounted for many, while in the interest of the road-mender many a noble Grey Wether has been led to slaughter to provide macadam for the roads. Hence it is not surprising that the number of Sarsen stones to be found on the Plain where Nature placed them is becoming less and less. Indeed, the time may yet come when they will be as extinct as the Great Bustard who once strutted among them, and their memory will survive only in their accidental use in a prehistoric monument like Stonehenge. THE FOREIGN STONES While the Sarsens usually awake the greatest interest by reason of their bulk, and the problem of how a primitive people was able to deal with them, a far greater problem is presented by the small uprights, or Foreign Stones, the like of which cannot be matched within a hundred miles of Salisbury Plain, while some can only be found upon the continent of Europe. Fragments carefully removed and submitted to mineralogists have made this fact abundantly clear, and consequently it is possible to arrive at the very definite conclusion that Stonehenge is certainly not a "Wiltshire" monument, and probably that it is not even "British" at all.