AiicieM ^fining on the Shores of Lake Superior. 181 



chisel is principally in the taper of the ax toward the head. No groove 

 or eye has been uoticed by which to insert a handle, but the Peruvians 

 had means of flistening a handle to a similar instrument without either. 

 There are also chisel-like tools from the Ohio mounds almost identical 

 Avith those I have already figured. James McBride, of Hamilton, 

 Butler County, Ohio, has in his possession four of them, found in 1855 

 near that place, that may be regarded either as chisels, axes, or adzes. 



How much time has passed- since these mines were wrought, or since 

 they were abandoned, is a question of great interest. The timber 

 found in some of the ancient mines is in a better state of preservation 

 than that of the Ohio mounds ; but it does not follow that it is more 

 recent. Most of the pieces exhumed were covered by water or wet 

 earth. In a northern climate the decay of wood is slower than in 

 warmer regions. The timber itself is mostly resinous, which assists in 

 its preservation. The wooden cob work that remains in the Ohio 

 tumuli, hitherto examined, always lies above water, and the loamy 

 earth in which it was l^uried does not wholly exclude the atmosphere. 



In the Grave Creek mound the timber was very much decayed, but 

 the chambers, including the skeletons, were elevated above the natural 

 surface, and the surrounding earth was dry. These circumstances 

 being considered, it does not follow that the wood work of the mounds 

 is the most ancient because it is the most decayed. 



The living trees now standing, with their roots entwined among the 

 mauls, skids and shovels of the old miners, are reliable witnesses as to 

 the least space of time since the mines were abandoned. The age of 

 such trees varies from 300 to 350 years. Beneath the shade of tho.^e 

 patriarchs of the forest are the prostrate and rotten trunks of a preced- 

 ing generation. 



General Harrison, in a discourse before the Historical Society of 

 Ohio, adds another score to the tally of ages that have passed since the 

 earthworks were evacuated. When ground that has been cleared of 

 its timber is abandoned, the second growth differs from the first in 

 kind. It is not until several generations of trees have disappeared, 

 that such places produce the varieties which constituted the original 

 forest. The same thing is observed on Point Keweenaw, where a 

 sweeping fire has consumed or deadened the resinous trees of the moun- 

 tains, the first succeeding growth is that of birch and aspen. 



In process of time, however, the balsam, cedar, pine, and hemlock 

 resume their ancient domain, overshadowing and obscuring the decid- 

 uous trees. On the ancient burrows, and in the old pits of Lake Su- 

 perior, the same kinds of timber flourish now as are observed in the 

 surrounding forest. These works could not have been carried on.with. 



