The southern wall on the first roof level still preserves very clear and distinct impressions of the rushes which were used in the construction of the roof. In some cases these impressions occur 3 inches above the top of the floor beams, in others directly above them, showing that the secondary series of poles was very irregularly placed. In the eastern and western walls the impressions of rushes are also clear, but there they are parallel with the wall surface. The rushes were about the thickness of a pencil.

The floor joists were 3 to 4 inches in diameter, and as a rule projected into the wall but 5 to 8 inches. In some places in the northern wall, however, they extended into the masonry as much as 3 feet 3 inches. The beams were doubtless cut by guess, at the place where trees of the requisite size were found, according to the method employed by the Pueblo Indians today, and if, as supposed, the northern room was built after the rest of the structure, the excess in length would necessarily be found in the northern wall.

In the roof construction previously described rushes or canes formed the third member, and in the northern room the wall is rough immediately above the impressions of rushes, and projects 8 to 12 inches. This feature is well marked; it may be a remnant of the clay covering of floor or roof, but it is almost too thick for that and possibly marks the position of a low bench, as previously suggested. The bottoms of the openings come just to or a trifle above the top of this marking.

[PLATE LVII]

BLOCKED OPENING IN WEST WALL

The walls of the western room were smoothly finished and the finish is well preserved, but here, as in the northern room, the exterior wall of the middle room was not finished above the second roof level, and there is no doubt that two stories above the ground were the maximum height of the western rooms, excluding the parapet. The eastern wall presents a marked double convexity while the western wall is comparatively straight in a horizontal line, but markedly concave vertically above the first roof level. Below this level it is straight. The floor beams were from 3 to 6 inches in diameter. The marks in the eastern wall show that the beams projected into it to a nearly uniform depth of 1 foot 4 inches. In the western wall, however, the depth varies from 1 to 3 feet. The beams which entered the eastern wall were very irregularly placed, the line rising in the center some 3 or 4 inches. The beams of the second roof level show the same irregularity and in the same place; possibly this was done to correct a level, for the same feature is repeated in the eastern room.

The walls of the southern room are perhaps better finished and less well constructed than any others in the building. The beam holes in the southern wall are regular, those in the northern wall less so. The beams used averaged a little smaller than those in the other rooms, and there is no trace whatever in the overhanging wall of the use of rushes or canes in the construction of the roof above. The walls depart considerably from vertical plane surfaces; the southern wall inclines fully 12 inches inward, while in the northeastern corner the side of a doorway projects fully 3 inches into the room. The broken condition of the southern wall indicates carelessness in construction. The weakest point in pisé construction is of course the framing around openings. In the southern wall the openings, being doubtless the first to give way, are now almost completely obliterated. In the center of the wall there were two openings, one above the other, but not a trace of lintels now remains, and the eastern half of the wall now stands clear from other walls. Probably there was also an opening near the southwestern corner of the room, but the lintels giving way the wall above fell down and, as shown on the ground plan (plate LII), filled up the opening. This could happen only with exceptionally light lintels and exceptionally bad construction of walls; one of the large blocks, before described as composing the wall, must have rested directly above the opening, which was practically the same size as the block.

The walls of the eastern room were well finished, and, except the western wall, in fairly good preservation. The floor beams were not placed in a straight line, but rise slightly near the middle, as noted above. The finish of some of the openings suggests that the floor was but 3 or 4 inches above the beams, and that the roughened surface, already mentioned, was not part of it. The northern wall of this room seems to have run through to the outside, on the east, as though at one time it formed the exterior wall of the structure; and the eastern wall of the building north of this room is separated from the rest of the wall by a wide crack, as though it had been built against a smooth surface. The western wall of this room shows clearly that in the construction of the building the floor beams were laid on the tops of the walls, and that the intervening spaces were filled with small lumps of material up to a level with or a little above the upper surface of the beams, the regular construction with large blocks being then resumed.

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.

OPENINGS.

The Casa Grande was well provided with doorways and other openings arranged in pairs one above the other. There were doorways from each room into each adjoining room, except that the middle room was entered only from the east. Some of the openings were not used and were closed with blocks of solid masonry built into them long prior to the final abandonment of the ruin.