Its dimensions, so far as I can make out, are as follows: it has a diameter of 310 to 315 feet for the whole mound, at its junction with the natural hill, on which it stands. The height is about 70 feet, made up of 14 feet for the slope of the hill to the floor of the central chamber, and 56 feet above it. The angle of external slope appears to be 35 degrees, or 5 degrees steeper than Silbury Hill, and consequently if there is anything in that argument, it may, at least, be a century or two older. The platform on the top is about 120 feet across, the whole being formed of loose stones, with the smallest possible admixture of earth and rubbish. [Illustration: 64. New Grange, near Drogheda.] Around its base was a circle of large stone monoliths (woodcut No. 63). They stand, according to Sir W. Wilde, 10 yards apart, on a circumference of 400 paces, or 1000 feet. If this were so, they were as nearly as may be 33 feet from centre to centre, and their number consequently must originally have been thirty, or the same number as at Stonehenge. From Bouie's plan I make the number thirty-two, but this is hardly to be depended upon. From this disposition it will be observed that if the tumulus were removed, or had never been erected, we should have here exactly such a circle--333 feet in diameter--as we find at Salkeld or at Stanton Drew, and it seems hardly doubtful but that such an arrangement as this on the banks of the Boyne gave rise to those circles which we find on the battle-fields of England two or three centuries later. Llwyd, in his letter to Rowland, mentions one smaller stone standing on the summit, but that had disappeared, as well as twenty of the outer circle, when Mr. Bouie's survey was made.