Evidently the early mason found the cutting of these tenons by no means an easy task, for, with two exceptions, the workmanship is not remarkable. Luckily for the observer to-day the tenon on the remaining upright of the Great Trilithon is very strongly marked, and stands out boldly on its apex, thus affording a clue to those existing on other stones. The mortice holes were easier to accomplish. A small depression may have been made first of all, and then a round stone inserted with sand and water. In this way a smooth hollow could soon be worn. This principle is and has been applied by stone-using peoples in all quarters of the globe. The rough dovetailing of the lintels of the outer circle would present no difficulty to users of the tools already mentioned. To-day the surfaces of the Sarsens bear undoubted signs of weather, but in the Stonehenge of yesterday the Sarsens were beautifully finished with rough tooling all over their surface. This final finish was achieved by the Quartzite Hammers (Class IV.). A very beautiful piece of this work was discovered by Mr. Gowland in 1901. In the process of raising the upright of the Great Trilithon, a thin slab of that part of the stone which had been buried in the foundation became detached. The tooling upon this fragment is absolutely perfect, and as clean and sharp as it was when it left the hand of the craftsman about four thousand years ago. So remarkable was the workmanship that experiments were made on pieces of Sarsen with various materials to endeavour to secure the same quality of surface, during which it was found that whereas the ordinary masons' chisels of to-day failed to produce the effect, a quartzite pebble used as a tool at once reproduced the character and surface of the original finish on the Trilithon. The foreign stones appear to have been treated in a very similar manner, but it is not possible to discuss this with the same detail as in the case of the Sarsens, for the body of the rock to be dealt with varied vastly in quality and fracture. The method of dressing by pounding was probably not adopted. Quantities of small chippings from the foreign stones were found in 1901, so many indeed as to justify the claim that these stones were actually dressed on the spot, and not partly shaped before being transported to the circle, as in the case of the Sarsens. This at once disposes of a popular and ingenious suggestion that the foreign stones were originally a temple elsewhere, and that in migrating to Salisbury Plain, the tribe had brought their temple with them. THE PROCESS OF ERECTION