upper and lower faces of the stone are substantially, but not exactly, parallel. It also shows one angle, which is substantially, but not exactly, a right angle and it was so adjusted that the long edge was on the doorway and short one in the wall of a chamber or apartment, with the right angle at
Fig. 41.—Stone from doorway. the corner between them. This stone was evidently prepared by fracture, probably with a stone maul, and the regularity of the breakage was doubtless partly to skill and partly to accident. It shows no marks of the chisel or the drove, or of having been rubbed, and where the square is applied to the sides or angles the rudeness of the stone is perfectly apparent.
Fig. 41. a represents a sandstone cut by American skilled workmen in the form of a brick, and it is intended to show by comparison the great difference between the dressed stone of the civilized man and the ruder stone of the mason in the condition of barbarism. The comparison shows that no instruments of exactness were used in the stone work of the pueblo, and that exactness was not attempted. But the accuracy of a practiced 
Fig. 41a.—A finished block of sandstone, for comparison with Fig. 41. eye and hand, such as their methods afforded, was reached, and this was all they attempted. With stones as rude as that shown in the figure, a fair and even respectable stone wall may be laid. The art of architecture in stone is of slow and difficult growth. Stone prepared by fracture with a stone hammer precedes dressed stone, which requires metallic implements. In like manner mud mortar or adobe mortar precedes a mortar of lime and sand. The Village Indians of America were working their way experimentally, and step by step, in the art of house-building, as all mankind have been obliged to do, each race for itself; and the structures the Village Indians have raised in various parts
