structure. [Illustration: PLATE VIII INTERIOR OF BUILDING A, FROM THE SOUTH.] What alone has saved the old church of Pecos from utter ruin has been its solid mode of construction. Entirely of adobe, its walls have an average thickness of 1.5 m.--5 ft. The adobe is made like that now used, wheat-straw entering into it occasionally; but it also contains small fragments of obsidian,--minute chips of that material and broken pottery. This makes it evident that the soil for its construction must have been gathered somewhere near the _mesilla_; and the suspicion is very strong on my part that it was the right bank of the _arroyo_ which furnished the material.[93] It is self-evident that the grounds which were used for that purpose must have antedated, in point of occupation, the date of the construction of the church by a very long period. I have measured all the adobe bricks of the church that are within easy reach, at various places, and found them alike. They all measure .55 m. × .28 m.--22 in. × 11 in.--and .08 m.--3 in.--in thickness. They are laid as shown in Plate I., Fig. 4. The mortar is, as the specimen sent by me will prove, of the same composition as the brick itself. The regularity with which these courses are laid is very striking. The timbers, besides, are all well squared; the ornaments, scrolls, and friezes are quaint, but not uncouth; there is a deficiency in workmanship, but great purity in outline and in design. To the south of the old church, at a distance of 4 m.--13 ft.--there is another adobe wall, rising in places a few metres above the soil; which wall, with that of the church, seems to have formed a covered passage-way. Adjoining it is a rectangular terrace of red earth, extending out to the west as far as the church front. A valuable record of the manner in which this terrace was occupied is preserved to us in the drawing of the Pecos church given by Lieutenant W. H. Emory in 1846. It appears that south of the church there was a convent;[94] and this is stated also by Sr. Ruiz. In fact, the walls, whether enclosures or buildings, which appear to have adjoined the church, extend south from it 74 m.--250 ft. Plate I., Fig. 2, gives an idea of their relative position, etc.: _c_ is 4 m.--13 ft.--wide; _d_ is 21 m. × 46 m.--70 ft. × 156 ft.; _e_ is 25 m. × 46 m.--82 ft. × 150 ft.; _f_ is 24 m. × 46 m.--78 ft. × 150 ft. The divisions are not strictly marked, and I forbear giving any lengths, since there is great uncertainty about them. The foundation walls, where visible, are generally about 0.60 m. to 0.75 m.--23 in. to 30 in.--wide, and composed of three rows of stones, set lengthwise, selected for size, and probably broken to fit.[95] [Illustration: PLATE I GENERAL PLAN OF RUINS OF PECOS.]