It stands, we read or were told, on Salisbury Plain.

To my uninformed, childish mind a plain anywhere was like the plain on which I was born--an absolutely level area stretching away on all sides into infinitude; and although the effect is of a great extent of earth, we know that we actually see very little of it, that standing on a level plain we have a very near horizon.

On this account any large object appearing on it, such as a horse or tree or a big animal, looks very much bigger than it would on land with a broken surface.
Oddly enough, my impossible Stonehenge was derived from a sober description and an accompanying plate in a sober work--a gigantic folio in two volumes entitled "A New System of Geography", dated some time in the eighteenth century.

How this ponderous work ever came to be out on the pampas, over six thousand miles from the land of its origin, is a thing to wonder at.

I remember that the Stonehenge plate greatly impressed me and that I sacrilegiously cut it out of the book so as to have it! Now we know, our reason tells us continually, that the mental pictures formed in childhood are false because the child and man have different standards, and furthermore the child mind exaggerates everything; nevertheless, such pictures persist until the scene or object so visualized is actually looked upon and the old image shattered.