32 . INDIANS OF THE SOUTHWEST. 
of this structure, which encloses 117 rooms, not counting 
those of the upper stories, were built of buff sandstone 
well dressed and laid with adobe mortar in regular 
courses. The irregularities are chinked with stone 
fragments. The corners of the walls are not bonded 
nor are the joints of the stones regularly broken in the 
Chiff 
courses. It seems that these devices and that of the 
arch and its keystone were unknown to the ancient 
peoples. These walls, which are from one to two feet 
in thickness, were generally plastered on the inside and 
sometimes on the outside with a yellow mud laid 
on and smoothed with the hands, the prints of which 
are often plainly visible. In a few cases, the walls are 
ornamented with paintings. 
