It is not often that an engineering operation has been made so subservient to the interests of science as the one we have dealt with in this chapter. It is satisfactory to know not only that much new knowledge has been acquired by Professor Gowland and his coadjutors, but that the famous leaning stone has now been set upright in such fashion that it will remain upright for hundreds of years. May the other leaning stones soon receive the same treatment. [15] Sir Richard Colt Hoare, _Ancient History of South Wiltshire_, p. 127. (London, 1812); W. Stukeley, _Stonehenge_, p. 46. (London, 1740). [16] _Wilts Archaeological and Natural History Magazine_, xxi. pp. 141-149. CHAPTER IX WAS THERE AN EARLIER CIRCLE? When we come to examine Stonehenge carefully in relation to the orientation theory, it soon becomes clear that its outer circle of upright stones with lintels, and the inner naos, built of trilithons, oriented in the line of the “avenue” and the summer solstice sunrise, are not the only things to be considered. These stones, all composed of sarsen, which, be it remarked, have been trimmed and tooled, are not alone in question. We have:-- (1) An interior circle broken in many places, and other stones near the naos, composed of stones, “blue stones,” which, as we have seen, are of an entirely different origin and composition. (2) Two smaller _untrimmed_ sarsen stones lying near the vallum, _not_ at the same distance from it, the line joining them passing nearly, but not quite, through the centre of the sarsen circle. The amplitude of the line joining them is approximately 26° S. of E. and 26° N. of W. Of these stones, the stump of the N.W. one is situated 22 feet from the top of the vallum according to the Ordnance plan. The S.E. stone has fallen, but according to careful observations and measurements by Mr. Penrose, when erect its centre was 14 feet from the top of the vallum. The centre of the line joining the stones is therefore about 4 feet to the S.E. of the axis of the present circles, which, it may be stated, passes 3 feet to the N.W. of the N.W. edge of the Friar’s Heel (see Fig. 24). [Illustration: FIG. 24.--Map of the Stones made by the Ordnance Survey.[17] A, N.W. stone; B, S.E. stone; C, Friar’s Heel; D, Slaughter stone.] There are besides these two large _untrimmed_ sarsen stones, one standing some distance outside the vallum, one recumbent lying on the vallum; both nearly, but not quite, in the sunrise line as viewed from the centre of the sarsen circle. These are termed the “Friar’s Heel” and “Slaughter Stone” respectively. I will deal with (1) first, and begin by another quotation from Mr. Cunnington, who displayed great acumen in dealing with the smaller stones not sarsens.