THE EARLY MAN OF NORTH AMERICA. 587 



race as identity of culture, while there is- great probability that botli 

 are implied. We must remember that as we go back in time we 

 should find the races of men less numerous than at present the 

 nearer we get to the common stock from which it is believed all man- 

 kind must have sprung. The survival of stone implements is not 

 unlike the persistence of older forms of life. The gai--pike [Lepidos- 

 teus bison) still inhabits our lakes, but the age when the ganoid type 

 of fishes prevailed has long gone by. In order to make the age of 

 the North American rough-stone implements clear, we must study the 

 geological evidence. 



Clay and gravel are made, we know, from the primitive rocks. 

 The atmosphere and the rain loosen lai'ge pieces of rock from the 

 mountains, and they are broken in the beds of streams by the action 

 of the water. The fine particles are produced by the rubbing of the 

 stones together ; the water grinds the broken rocks down smooth, 

 and makes pebbles of them. Gravel, sand, and clay, produced in this 

 manner, become sorted out by the action of the water, or stratified. 

 From a study of the action of existing glaciers or ice-masses on the 

 Alps, or in the North, it is seen that clay and gravel are also made 

 from the primitive rock, ground out by the slow movement of the ice. 

 The mass of dirt and stones is discharged at the edge of the glacier 

 much as a bar is formed by a river. 



But there is this difference, that the bar made by the glacier, and 

 which we call a moraine, contains its gravel and clay and bowlders, in 

 a confused mass, with little sorting, and thus xinstratified. Now, these 

 rough-stone implements have been found in New Jersey by Dr. Ab- 

 bott, in unstratified beds of material, which are evidently, from their 

 composition, ancient moraines. There are, we know, different degrees 

 of evidence. A fact may be either demonstrated, or shown to be prob- 

 able, or possible. I leave it to you to judge whether these circum- 

 stances do not demonstrate that North American rough-stone imple- 

 ments are as old as the beds in which they are found. To me, it 

 seems clear that the men who used these rough tools dwelt on the 

 edge of the glacier, and their implements have become buried in the 

 moraines which were forming at many different points during the ice- 

 period. Nor can we refuse to admit what this demonstrated fact 

 implies, the great age of man in North America. I have taken, on 

 a former occasion, the sum of 100,000 years as the time that has 

 probably elapsed since the retiring of the glacier from the valleys 

 of the White Mountains, in New Hampshire. This figure was ar- 

 rived at after a calculation based on the ratio of movement of bodies 

 of ice, and the round number may be considered as an under rather 

 than over estimate. But, at whatever time during the glacial epoch 

 the moraine was formed, in which Dr. Abbott found these implements 

 of early man, it is quite clear that this knowledge alone will not give 

 us the duration of man's existence in North America ; for it is certain 



