Cosmos Mindeleff

“ When abandoned, however, sapping at the ground level would commence, and would in time level all the walls; yet in the two centuries which have elapsed since Padre Kino's visit—and the Casa Grande was then a ruin—there has been but little destruction, the damage done by relic hunters in the last twenty years being in fact much greater than that wrought by the elements in the preceding two centuries. The relic hunters seem to have had a craze for wood, as the lintels of openings and even the stumps of floor joists have been torn out and carried away. ”

“ After a rain the ground, and that portion of the walls at present below its surface, retains moisture much longer than the part of the walls which stands clear; the moisture rises by capillary attraction a foot or two above the ground surface, rendering the walls at this level softer than elsewhere, and as this portion is more exposed to the flying sand which the wind sweeps over the ground it is here that erosion attains its maximum. The wall is gradually cut away at and just above the ground surface until finally the base becomes too small to support it and it falls en masse. ”

“ The tops of the walls, while rough and much eroded, are approximately level. The exterior surface of the walls is rough, as shown in the illustrations, but the interior walls of the rooms are finished with a remarkable degree of smoothness, so much so as to attract the attention of everyone who has visited the ruin. Mange, who saw the ruin with Padre Font in 1697, says the walls shine like Puebla pottery, and they still retain this finish wherever the surface has not cracked off. ”

“ The long north and south ridge which forms the southeastern corner of the area, with other ridges extending westward, is quite wide on top, wide enough to accommodate a single row of rooms of the same width as those of the ruin, and it is hardly reasonable to suppose that a wall would be built 10 or 12 feet wide when one of 4 feet would serve every purpose to which it could possibly be put. ”

“ The Casa Grande was undoubtedly built and occupied by a branch of the Pueblo race, or by an allied people. Who these people were it is impossible to determine finally from the examination of one ruin, but all the evidence at hand suggests that they were the ancestors of the present Pima Indians, now found in the vicinity and known to have formerly been a pueblo-building tribe. ”

“ External appearance is a very unsafe criterion of age, although in some cases, like the present, it affords a fair basis for hypothesis as to comparative age; but even in this case, where the various portions of the group have presumably been affected alike by climatic and other influences, such hypothesis, while perhaps interesting, must be used with the greatest caution. ”

“ The surface erosion of a standing wall of grout, such as these under discussion, is very slight; photographs of the Casa Grande ruin, extending over a period of sixteen years, and made from practically the same point of view, show that the skyline or silhouette remained essentially unchanged during that period, every little knob and projection remaining the same. It is through sapping or undermining at the ground surface that walls are destroyed. ”

“ There are also some small depressions in the immediate vicinity of the Casa Grande ruin and of the mounds north of it.
With a single exception none of these depressions are so situated that they could be used as reservoirs for the storage of water collected from the surface, and the catchment area of the depressions is so small and the rate of evaporation in this area so great that their use as reservoirs is out of the question. It is probable that all of the smaller depressions represent simply sites where building material was obtained. ”

“ Its literature, which extends over two centuries, is voluminous, but of little value to the practical scientific worker, since hardly two descriptions can be found which agree. The variations in size of the ruin given by various authors is astonishing, ranging from 1,500 square feet to nearly 5 acres or about 200,000 square feet in area. These extreme variations are doubtless due to difference of judgment as to what portion of the area covered by remains of walls should be assigned to the Casa Grande proper, for this structure is but a portion of a large group of ruins. ”

“ Then and not till then surface erosion becomes an important factor and the profile of 301 the mass becomes finally rounded. But it will be readily seen that a slight difference of texture, or thickness, or exposure, or some trifling difference too minute for observation, might easily add many decades to the apparent age of a mound. The walls once fallen, however, the rounding or smoothing of the mounds would probably proceed at an equal rate throughout the group, and study of the profile gives a fairly good estimate as to the comparative age of the mounds. ”

“ The northern and southern rooms do not afford as good bases for comparison, as a corner is missing in each; but measurements to a point where the interior wall surfaces would intersect if prolonged, show variations of from 6 inches to a foot. The statement that the ruin exhibits exceptional skill in construction on the part of the builders, is not, therefore, supported by facts. ”

“ In the middle room many blocks bearing the imprint of grass and rushes were found, and the rough marking of the walls just above the floor beams is covered in places in this room with masonry composed of these grass marked blocks projecting some distance into the room, indicating that in this room at least they mark the position of a bench. These blocks occupy the whole thickness of the setback at the second roof level—perhaps an indication that the upper story was added after the building was occupied. ”

“ The Casa Grande ruin is often referred to as an adobe structure. Adobe construction, if we limit the word to its proper meaning, consists of the use of molded brick, dried in the sun but not baked. Adobe, as thus defined, is very largely used throughout the southwest, more than nine out of ten houses erected by the Mexican population and many of those erected by the Pueblo Indians being so constructed ”

“ This area is doubtless the one measured in 1776, by Padre Font, whose description, was copied by later writers, and whose measurements were applied by Humboldt and others to the ruin itself. Font gave his measurements as those of a circumscribing wall, and his inference has been adopted by many, in fact most, later writers. A circumscribing wall is an anomalous feature, in the experience of the writer, and a close inspection of the general map will show that Font's inference is hardly justified by the condition of the remains today. ”

“ About a mile and a half toward the north a fringe of cottonwood trees marks the course of the river, beyond which the plain continues, broken somewhat by hills and buttes, until the view is closed by the Superstition mountains. ”

“ It will be noticed that while most of the mounds which mark the sites of former structures rise but 10 feet or less above the surrounding level, the profiles vary considerably, some being much more smoothed off and rounded than others, the former being shown on the map by even, "flowing" contours, while the latter are more irregular; and it will be further noticed that the irregularity reaches its maximum in the vicinity of the Casa Grande ruin proper, where the ground surface was more recently formed, from the fall of walls that were standing within the historical period. ”

“ In this instance the irregularity indicates a recent formation of surface; for at this point many walls now marked only by mounds were standing within the historical period. External contour is of course a product of erosion, yet similarity of contour does not necessarily indicate either equal erosion or equal antiquity. Surface erosion does not become a prominent factor until after the walls have fallen, and one wall may easily last for a century or two centuries longer than another similarly situated. ”

“ In the Casa Grande ruin a series of light joists or heavy poles was laid across the shorter axis of the room at the time the walls were erected; these poles were 3 to 6 inches in diameter, not selected or laid with unusual care, as the holes in the side walls which mark the places they occupied are seldom in a straight line, and their shape often indicates that the poles were quite crooked. Better executed examples of the same construction are often found in northern ruins. ”

“ The opening was blocked by solid masonry built into it and completely filling it up to within 10 inches of the top. This upper space, which is on a level with the upper hole in the middle room, seems to have been purposely left to allow an outlook from that room. The filling block is level on top and flush with the wall inside and out. At a height of 12 inches above the lower edge of the floor beams below it, and perhaps 3 inches above the floor, is the lower edge of a roughly square opening a foot across, cut 316 out from the block itself and inclined slightly downward toward the exterior. ”

“ An inspection of the map will show a number of depressions, some of quite large area, indicated by dotted contour lines. The principal one occurs a little west of the center of the area, and is worth more than a passing notice since similar structures are widely distributed throughout this region. It may be roughly characterized as a mound with excavated center. The ground for some distance about the structure (except for two depressions discussed later) is quite flat. From this 304 flat surface as a base the structure rises to a height of 5 feet. ”

“ The application of the hypothesis to the map brings out some interesting results. In the first place, it may be seen that in the lowest mounds, such as those in the northwestern corner of the sheet, on the southern margin, and southwest of the well-marked mound on the eastern margin, the contours are more flowing and the slopes more gentle than in others. ”

“ In addition to its three doorways, all in the eastern wall, the middle tier of rooms was well provided with niches and holes in the walls, some of them doubtless utilized as outlooks. On the left of the upper doorway are two holes, a foot apart, about 4 inches in diameter, and smoothly finished. Almost directly above these some 3 feet, and about 2 feet higher than the top of the door, there are two similar holes. Near the southern end of the room in the same wall there is another round opening a trifle larger and about 41⁄2 feet above the floor level. ”

“ The Casa Grande ruin is located near the southwestern corner of the group, and the ground surface for miles about it in every direction is so flat that from the summit of the walls an immense stretch of country is brought under view. On the east is the broad valley of Gila river rising in a great plain to a distant range of mountains. ”