A lime-kiln formerly stood in a grass-field near Leith Hill Place, in Surrey, and was pulled down 35 years before my visit; all the loose rubbish had been carted away, excepting three large stones of quartzose sandstone, which it was thought might hereafter be of some use.  An old workman remembered that they had been left on a bare surface of broken bricks and mortar, close to the foundations of the kiln; but the whole surrounding surface is now covered with turf and mould.  The two largest of these stones had never since been moved; nor could this easily have been done, as, when I had them removed, it was the work of two men with levers.  One of these stones, and not the largest, was 64 inches long, 17 inches broad, and from 9 to 10 inches in thickness.  Its lower surface was somewhat protuberant in the middle; and this part still rested on broken bricks and mortar, showing the truth of the old workman’s account.  Beneath the brick rubbish the natural sandy soil, full of fragments of sandstone, was found; and this could have yielded very little, if at all, to the weight of the stone, as might have been expected if the sub-soil had been clay.  The surface of the field, for a distance of about 9 inches round the stone, gradually sloped up to it, and close to the stone stood in most places about 4 inches above the surrounding ground.  The base of the stone was buried from 1 to 2 inches beneath the general level, and the upper surface projected about 8 inches above this level, or about 4 inches above the sloping border of turf.  After the removal of the stone it became evident that one of its pointed ends must at first have stood clear above the ground by some inches, but its upper surface was now on a level with the surrounding turf.  When the stone was removed, an exact cast of its lower side, forming a shallow crateriform hollow, was left, the inner surface of which consisted of fine, black mould, excepting where the more protuberant parts rested on the brick-rubbish.  A transverse section of this stone, together with its bed, drawn from measurements made after it had been displaced, is here given on a scale of 1/2 inch to a foot (Fig. 2).  The turf-covered border which sloped up to the stone, consisted of fine vegetable mould, in one part 7 inches in thickness.  This evidently consisted of worm-castings, several of which had been recently ejected.  The whole stone had sunk in the thirty-five years, as far as I could judge, about 11/2 inch; and this must have been due to the brick-rubbish beneath the more protuberant parts having been undermined by worms.  At this rate, the upper surface of the stone, if it had been left undisturbed, would have sunk to the general level of the field in 247 years; but before this could have occurred, some earth would have been washed down by heavy rain from the castings on the raised border of turf over the upper surface of the stone.

[Illustration:  FIG. 2. 
Transverse section across a large stone, which had lain on a
    grass-field for thirty-five years. aa, general level of the
    field.  The underlying brick of rubbish has not been represented.]