310 CASA GRANDE RUIN. [eth.ann. 13 



subsequent to the Spanish conquest. Its discovery, therefore, in the 

 Casa Grande would be important ; but no trace of it can be found. The 

 walls are composed of huge blocks of earth, 3 to 5 feet long, 2 feet high, 

 and 3 to 4 feet thick. These blocks were not molded and placed in 

 situ, but were manufactured in place. The method adopted was prob- 

 ably the erection of a framework of canes or light poles, woven with 

 reeds or grass, forming two parallel surfaces or planes, some 3 or 4 feet 

 apart and about 5 feet long. Into this open box or trough was rammed 

 clayey earth obtained from the immediate vicinity and mixed with 

 water to a heavy paste. When the mass was sufficiently dry, the frame- 

 work was moved along the wall and the operation repeated. This is 

 the typical pise or rammed-earth construction, and in the hands of 

 skilled workmen it suffices for the construction of quite elaborate build- 

 ings. As here used, however, the appliances were rude and the work- 

 men unskilled. An inspection of the illustrations herewith, especially 

 of plate LV, showing the western wall of the ruin, will indicate clearly 

 how this work was done. The horizontal lines, marking what may be 

 called courses, are very well defined, and, while the vertical joints are 

 not apparent in the illustration, a close inspection of the wall itself 

 shows them. It will be noticed that the builders were unable to keep 

 straight courses, and that occasional thin courses were put in to bring 

 the wall up to a general level. This is even more noticeable in other 

 parts of the ruin. It is probable that as the walls rose the exterior 

 surface was smoothed with the hand or with some suitable implement, 

 but it was not carefully finished like the interior, nor was it treated 

 like the latter with a specially jirepared material. The material em- 

 ployed for the walls was admirably suited for the purpose, being 

 when dry almost as hard as sandstone and practically indestructible. 

 The manner in which such walls disintegrate under atmospheric influ- 

 ences has already been set forth in detail in this report. An inhab- 

 ited structure with walls like these would last indefinitely, provided 

 occupancy continued and a few slight repairs, which would accom- 

 pany occupancy, were made at the conclusion of each rainy season. 

 When abandoned, however, sapping at the ground level would com- 

 mence, and would in tmie level all the walls; yet in the two ceiitu- 

 ries 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 open- 

 ings and even the stumps of floor joists have been torn out and carried 

 away. The writer has been reliably informed that as late as twenty 

 years ago a portion of the floor or roof in one of the rooms was still in 

 place, but at the present day nothing is left of the floors except marks 

 on the vertical walls, and a few stumps of floor joists, deeply imbedded 

 in the walls, and so high that they can not be seen from the ground. 



