According to this view, the amount of tin added was an index of the casting process and was not added to harden the tool. Microscopic studies of typical tools also show that the combination of tin and copper was often made in the melting pot and not in the smelter. We may, therefore, consider it as settled that the art of making bronze was known in the New World, though the real purpose of the process may have been the facilitation of casting.
In both Mexico and the Andean countries of South America, gold and silver were skilfully worked by casting, soldering, hammering, and inlaying. The graves and sacred lakes of the Andes still yield very fine examples of this art, most of which are melted down to be sold as bullion. From Ecuador, we have a few examples of gold objects overlaid with platinum, which shows how truly meritorious were the aboriginal metal working arts of the New World.
1. Holmes, 1897. I.
2. Spencer and Gillen, 1899. I.
3. Boas, 1909. I.
4. Smith, H. I., 1900. I.
5. Rau, 1873. I.
6. Boas, 1909. I.
7. Moorehead, 1910. I.
8. Laufer, 1912. I.
9. Skinner, 1909. I.
10. Brower, 1904. I.
11. Moorehead, 1910. I.
12. McGuire, 1899. I.
13. Holmes, 1897. I.
14. Holmes, 1901. I.
15. Moorehead, 1910. I.
16. Cushing, 1895. I.
17. Stefánsson, 1914. I.
18. Mead, 1915. I.
19. Mathewson, 1915. I.
