CONCLUSIONS ON ANCIENT CLIMATES. Ae 
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, and the skeletons and implements 
found with it, belong to an age when the use of iron was not 
known to the builders. Dut 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, and large vessels of similar construction are used by the 
islanders of the Malay archipelago. Nor is the occurrence of 
flint 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 implements 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 neigh- 
borhood;” * and the North American Indians now manufacture 
weapons of stone, and even of glass, chipping them in the latter 
case out of the bottoms of thick bottles, with great facility.+ 
We may also be misled by our ignorance of the commercial 
relations existing between savage tribes. Extremely rude 
* Antiquity of Man, p. 377. 
+ ‘‘One of the Indians seated himself near me, and made from a fragment 
of quartz, with a simple piece of round bone, one end of which was hemi- 
spherical, with a small crease in it (as if worn by a thread) the sixteenth of an 
inch deep, an arrow head which was very sharp and piercing, and such as they 
use on all their arrows. The skill and rapidity with which it was made, with. 
out a blow, but by simply breaking the sharp edges with the creased bone by 
the strength of his hands—for the crease merely served to prevent the instru- 
ment from slipping, affording no leverage—was remarkable.”—Reports of Hz- 
plorations and Surveys for Pacific Railroad, vol. ii., 1855, Lieut. Breexwrrn’s 
Report, p. 43. See also American Naturalist for May, 1870, and especially 
STEVENS, Flint Chips, London, 1870, pp. 77 et seq. 
Mariette Bey lately saw an Egyptian barber shave the head of an Arab with 
a flint razor. 
