1875.] 4:Oi [Cope. 



only water holders observed were the earthenware pots buried in the 

 ground, which did not exceed eighteen inches in diameter. There is, 

 however, no doubt that these people manufactured great numbers of 

 these narrow-necked globular vessels, whose principal use must have 

 been the holding of fluids, and chiefly of water. Nevertheless, it is 

 scarcely conceivable that the inhabitants of the houses now so remote 

 from water, could have subsisted under the present conditions. Pro- 

 fessor Newberry (Ives' Report) is of the opinion that a diminution in the 

 amount of rain-fall over this region has taken place at no very remote 

 period in the past, and cites the death of forests of pine trees which still 

 stand, as probably due to increasing drought. It is of course evident, 

 that erosive agencies were once much more active in these regions than 

 at present, as the numerous and vast canons testify, but that any change 

 sufficient to affect this process should have occurred in the human period, 

 seems highly improbable. In other words, the process of cutting can- 

 ons of such depth in rocks of such hardness is so slow, that its early 

 stages which were associated with a different distribution of surface 

 water supply, must have far antedated the human period. 



Nevertheless, if we yield to the supposition that during the period of 

 residence of the ancient inhabitants the water supply from rains was 

 greater than now, what evidence do we possess which bears on the age of 

 that period ? There is no difference between the vegetation found grow- 

 ing in these buildings, and that of the surrounding hills and valleys ; 

 the pines and sage-brush are of the same size, and to all appearances of 

 the same age. I should suppose them to be contemporaiy in every re- 

 spect. In the next place, the bad-lands have undergone a definite amount 

 of atmospheric erosion since the occupancy of the houses which stand 

 on their summits. The rate of this erosion under present atmospheric 

 influences is undoubtedly very slow. The only means which suggested 

 itself as available at the time, was the calculation of the age of pine 

 trees which grow near the base of the bluffs. These have, of course, 

 attained their present size since the removal of the front of the stratum 

 from the position which the trees now occupy, so that the age of the 

 latter represents at least the time required for the erosion to have re- 

 moved the bluif to its present position. But how much time elapsed 

 between the uncovering of the position now occupied by the tree and its 

 germination, there is, of course, no means of ascertaining. My assistant, 

 an educated and exact man, counted the rings in a cut he made into the 

 side of a piiion {Pinus cemhroides) which stood at a distance of forty 

 feet from a bluff, not far from a locality of ruins. In a quarter of an 

 inch of solid wood he found sixteen concentric layers, or sixty four to an 

 inch. The tree was probably twenty inches in diameter, which gives 

 six hundred and forty annual growths. The pinon is a small species, 

 hence the closeness of the rings in an old tree. 



At present it is only possible to speculate on the history of the builders 

 of these houses, and the date of their extinction. The tribes of Indians 

 at present inhabiting the region at irregular intervals, can give no account 



