The above catalogue of stones may not convey very much to the ordinary visitor, and has only been inserted for the sake of completeness; or for the information of geologists who may be concerned with this aspect of the history of the monument. The conclusions to be drawn from such a list, however, are not without interest to the general reader. From the varied fragments found, it is apparent that some six, or perhaps seven, different classes of stone were used for the small uprights, but that only the harder and more durable rocks (the diabase, rhyolite, etc.) have survived. The softer rocks (basic tuffs, grey wackes, flagstones, and slates), being more easily broken, have fallen victims to the souvenir hunter, and to the action of the weather, rain, and frost. Originally, as has already been stated, the foreign stones numbered forty-five, disposed as follows: thirty in the outer circle, and fifteen in the inner horseshoe. To-day only nineteen exist in the outer circle, and eleven in the inner horseshoe. A very striking proof that many of these foreign stones have disappeared, is to be found in the wide gaps which exist to-day in certain parts of the circle. That such gaps were originally filled by standing stones is beyond question, indeed, the base of a "schistose" stone (see Class 3 in the Lithology above) was actually discovered by Mr. Cunnington in the course of his investigations into the nature of the rocks composing Stonehenge. It is highly probable that careful and scientific excavation may add greatly to our knowledge in this direction. There is yet one other point of interest in connection with these foreign stones. On entering the circle from the north-east (the usual path taken by visitors) a recumbent foreign stone will be noticed on the left-hand side, which has two cavities worked in it. This is the only worked foreign stone in the whole monument, and at first sight these cavities may possibly suggest themselves as "mortise holes" similar to those on the Sarsen trilithons, to be described later. It has even been suggested that the small uprights once carried imposts, or lintel stones similar to the trilithons, on the evidence of this one stone. Such a theory, however attractive, should be accepted with due caution, for the cavities on the stone are far from the ends, and situated too close together to justify a comparison with the existing Sarsen trilithons of the outer circle. This stone has never yet been explained and its position defined, consequently it is omitted from the frontispiece. THE STONES WITHOUT THE CIRCLE Outside the circle of Trilithons stand three stones which have not as yet been described in detail, since they do not fall within the geometrical arrangement of the circle. They are, however, of the highest importance, as it is from them, and from their position, that it is possible to gather some conclusions as to one use to which the structure may have been put.