ARTS OF RUDE TRIBES. 
17 
tlie countries they occupied began. The plants and animals 
that furnished the relics found in the deposits were certainly 
contemporaneous with man ; for they are associated with his 
works, and have evidently served his uses. In some cases, the 
animals belonged to species well ascertained to he now alto¬ 
gether extinct; in some others, both the animals and the 
vegetables, though extant elsewhere, have ceased to inhabit 
the regions where their remains are discovered. From the 
character of the artificial objects, as compared with others 
belonging to known dates, or at least to known periods of 
civilization, ingenious inferences have been drawn as to their 
age; and from the vegetation, remains of which accompany 
them, as to the climates of Central and Northern Europe at 
the time of their production. 
There are, however, sources of error which have not always 
been sufficiently guarded against in making these estimates. 
When a boat, composed of several pieces of wood fastened 
together by pins of the same material, is dug out of a bog, it 
is inferred that the vessel, the skeletons, and the implements 
found with it, belong to an age when the use of iron was not 
known to the builders. But this conclusion is not warranted 
by the simple fact that metals were not employed in its con¬ 
struction ; for the Nubians at this day build boats large enough 
to carry half a dozen persons across the Nile, out of small 
pieces of acacia wood pinned together entirely with wooden 
bolts. Nor is the occurrence of Hint arrow heads and knives, 
in conjunction with other evidences of human life, conclusive 
proof as to the antiquity of the latter. Lyell informs us that 
some Oriental tribes still continue to use the same stone imple¬ 
ments as their ancestors, “ after that mighty empires, where 
the use of metals in the arts was well known, had flourished 
for three thousand years in their neighborhood; ” * and the 
North American Indians now manufacture and use weapons 
of stone, and even of glass, chipping them in the latter case 
out of the bottoms of thick bottles, with great facility.j* 
* Antiquity of Man, p. 377. 
f “ One of them [the Indians] seated himself near me, and made from 
2 
