in the two areas: linear pieces were removed by grooving and breaking; cutting was by sawing or hacking deep notches, then breaking. On the whole, the art seems most intense among the Eskimo, and in comparison with North America, the southern continent appears rather weaker in bone work, particularly in the simpler culture of Tierra del Fuego. Again, in the Antilles we find the thick parts of shells used for making celts and other tools.
Of ornaments, pendants, and beads, there are great varieties of various materials from both continents. Even pearl beads were extensively used by the Ohio mound builders.
MINES AND QUARRIES
Under the general head of materials dug from the earth, we have an important series of archæological topics. Notwithstanding that many of these aboriginal mining operations must have survived well down into the period of colonization, none was carefully observed by explorers. In the United States and Canada, copper, cinnabar, ocher, salt, alum, clay, steatite, flint and other flakable stones, catlinite, turquoise, coal (for making ornaments), and mica were dug out. Practically all such operations were confined to the eastern maize area and the Pueblo habitat. South of the Rio Grande, gold, silver, and copper, and in the Andean region, gold, copper, tin, silver, and platinum were worked. Here also, stone-quarrying operations were extensive, but outside of the Andean highlands we have practically no evidence of mining or quarrying in South America.
Archæological interest centers chiefly in flint workings and copper mining. In the case of the former, we have sites where a large part of the surface has been dug over for quartzite and other nodular forms. Of such sites the best known is that studied by Holmes at Washington, District of Columbia. The most extensive diggings seem to be those explored by Smith in Wyoming, which appear as part of a chain reaching into Oklahoma. Other noted sites are Flint Ridge, Ohio; Mill Creek, Illinois; Hot Springs, Arkansas; and two in Pennsylvania. In some of these the pits reach a depth of twenty
- Holmes, 1897. I.