702 THE ICE AGE IN NORTH AMERICA. 



iron, which indicated considerable age, and came up in the 

 sand-pump from a depth of three hundred and twenty feet. 

 Near the surface the well penetrated a stratum of basalt, fifteen 

 feet thick. Below this basalt there were alternate beds of clay 

 and quicksand to the depth mentioned, where the sandstone 

 rock was encountered. The well was tubed with heavy iron 

 tubing six inches in diameter, so that there could be no mistake 

 about the occurrence of the image at the depth stated. The 

 detailed evidence was published by me in the " Proceedings of 

 the Boston Society of Natural History " for January, 1890. 

 During the following summer, I visited the locality and found 

 ample confirmation of it. 



It is proper also to be stated that Mr. G. M. Cumming, 

 general manager of the Union Pacific lines in that district was 

 on the ground the day the "find" was made, and carefully 

 scanned the evidence, with the conclusion that there was no 

 doubt of the facts as given. Probably no person in the world 

 was better able than he to judge of the evidence. Later, other 

 officials of the railroad who had interests in the vicinity took 

 pains at my suggestion to re-examine the evidence with the 

 result of confirming it in every respect. On the other hand, 

 no one has come forward to challenge the evidence except on 

 purely d priori grounds arising from preconceived opinions 

 of the extreme antiquity of the deposits in which it is said 

 to have been found. Close attention to the accompanying 

 conditions will, however, I think modify these preconceptions. 



In the valley between the Boise and Snake Rivers, in south- 

 western Idaho, where Nampa is situated, there is an area of sev- 

 eral hundred square miles covered with fresh-appearing basalt, 

 which apparently came from vents thirty or forty miles to the 

 east, but in its western flow barely extended five miles beyond 

 Nampa. Below that point there is no lava for seventy miles. 

 The clay and quicksand covering the stratum in which the 

 image was found would seem to have accumulated in the valley 

 of a stream having access to such an amount of sedimentary 

 material that for a time it filled up rather than eroded its chan- 

 nel. Apparently the conditions favorable for such effects would 



