290 SMITHSONIAN MISCELLANEOUS COLLECTIONS [VOI,. 50 



attention had been paid to the mounds, and little was known of their 

 contents and their relation to the main building up to the inception 

 of this work. The mounds are arranged in several groups or clus- 

 ters, that for reasons which it is hoped may appear sufficiently 

 good are called "compounds." To distinguish it from other groups 

 of the same type, the cluster chosen especially for excavation in 

 1906-07 is called Compound A. 



The appropriation for 1906-07 sufficed to open the mounds and 

 to remove the accumulated earth from about three-fifths of Com- 

 pound A. In the course of this work there was found a wall which 

 surrounds not only Casa Grande but also forty-three large rooms 

 forming several clusters, some of which are larger than the historic 

 Great House of Father Kino. 1 



The newly discovered walls have been repaired and protected 

 from future harm, so that the visitor may now have some idea of the 

 original appearance of the compound. The debris that had accumu- 

 lated for centuries about the walls has been removed to a consider- 

 able distance, and they now stand out in bolder relief than they did 

 when the Spanish padres first saw them. Where six months ago 

 were mounds now rise houses with walls, floors, and doorways 

 through which the visitor can walk, as did the ancient people before 

 the place was deserted. 



The removal of earth that had accumulated in the rooms and 

 plazas from the surface down to the floor was in itself no small 

 task, but this was only one phase of the work accomplished in 

 making Casa Grande an "exhibition ruin." For the first time in the 

 history of archeological excavations in our Southwest, an effort was 

 made to repair and protect the walls that were uncovered, so that 

 they should not suffer from the elements. As the walls of the houses 

 are constructed of material which is easily eroded, their permanent 

 preservation necessitated drains for carrying off the water, lest it 

 penetrate the foundations and cause disintegration. The bases of 

 all the walls excavated were treated with cement laid on an inclined 

 plane of clay, forming a watershed by which the rain is deflected 

 from the walls into small drains opening into a large ditch at the 

 northeast corner, which ultimately conducts the water to a distant 

 depression. About three-fourths of a mile of wall was given this 

 basal protection. 



1 This wall is figured by Font and Bandelier, but is not recognized as such 

 by Cosmos MindelefT. 



