Where exceptionally large blocks of stone are available they have been utilized in an upright position, and occur at greater or less intervals along the thin walls of dry masonry. An example of this use was seen in a garden wall on the west side of Walpi, where the stones had been set on end in the yielding surface of a sandy slope among the foothills. A similar arrangement, occurring close to the houses at Ojo Caliente, is illustrated in Pl. XCII. Large, upright slabs of stone have been used by the pueblo builders in many ways, sometimes incorporated into the architecture of the houses, and again in detached positions at some distance from the villages. Pls. [XCIII] and [XCIV], drawn from the photographs of Mr. W. H. Jackson, afford illustrations of this usage in the ancient ruins of Montezuma Canyon. In the first of these cases the stones were utilized, apparently, in house masonry. Among the ruins in the valley of the San Juan and its tributaries, as described by Messrs. W. H. Holmes and W. H. Jackson, varied arrangements of upright slabs of stone are of frequent occurrence. The rows of stones are sometimes arranged in squares, sometimes in circles, and occasionally are incorporated into the walls of ordinary masonry, as in the example illustrated. Isolated slabs are also met with among the ruins. At K’iakima, at a point near the margin of the ruin, occurs a series of very large, upright slabs, which occupy the positions of headstones to a number of small inclosures, thought to be mortuary, outlined upon the ground. These have been already described in connection with the ground plan of this village.
Plate XCII. An inclosing wall of upright stones at Ojo Caliente.
The employment of upright slabs of stone to mark graves probably prevailed to some extent in ancient practice, but other uses suggest themselves. Occupying a conspicuous point in the village of Kin-tiel ([Pl. LXIII]) is an upright slab of sandstone which seems to stand in its original position undisturbed, though the walls of the adjoining rooms are in ruins. A similar feature was seen at Peñasco Blanco, on the east side of the village and a short distance without the inclosing wall. Both these rude pillars are, in character and in position, very similar to an upright stone of known use at Zuñi. A hundred and fifty feet from this pueblo is a large upright block of sandstone, which is said to be used as a datum point in the observations of the sun made by a priest of Zuñi for the regulation of the time for planting and harvesting, for determining the new year, and for fixing the dates of certain other ceremonial observances. By the aid of such devices as the native priests have at their command they are enabled to fix the date of the winter solstice with a fair degree of accuracy. Such rude determination of time was probably an aboriginal invention, and may have furnished the motive in other cases for placing stone pillars in such unusual positions. The explanation of the governor of Zuñi for a sun symbol seen on an upright stone at Matsaki has been given in the description of that place. Single slabs are also used, as seen in the easternmost room group of Tâaaiyalana, and in the southwestern cluster on the same mesa, in the building of shrines for the deposit of plume sticks and other ceremonial objects.
Plate XCIII. Upright blocks of sandstone built into an ancient pueblo wall.
An unusual employment of small stones in an upright position occurs at Zuñi. The inclosing wall of the church yard, still used as a burial place, is provided at intervals along its top with upright pieces of stone set into the joints of a regular coping course that caps the wall. This feature may have some connection with the idea of vertical grave stones, noted at K’iakima. It is difficult to surmise what practical purpose could have been subserved by these small upright stones.