CHAPTER IX. ALLOYS. The Age of Bronze—An intermediate Copper Age—European Copper Implements—Native Silver and Copper—Tin and Copper Ores—The Cassiterides—Ancient Sources of Tin—Arts of Yucatan—Alloyed Copper Axe-Blades—Bronze Silver-Mining Tool—Peruvian Bronzes—Primitive Mining Tools—Native Metallurgic Processes—Metallic Treasures of the Incas—Traces of an Older Race—Peruvian History—The Toltecs and Mexicans—Adjustment of Calendar—Barbarian Excesses—Native Goldsmith’s Work—Panama Gold Relics—Mexican Metallic Currency—Experimental Processes—Ancient European Bronzes—Tests of Civilisation—Ancient American Bronzes—The Native Metallurgist, 229 CHAPTER X. THE MOUND-BUILDERS. Earth Pyramids—Monuments of the Mound-Builders—Seats of Ancient Population—Different Classes of Works—Ancient Strongholds—Natural Sites—Fort Hill, Ohio—Iroquois Strongholds—Analogous Strongholds—Fortified Civic Sites—Sacred Enclosures—Newark Eagle Mound—Geometrical Earthworks—Plan of Newark Earthworks, Ohio—A Standard of Measurement—Diversity of Works—Evidence of Skill—The Cincinnati Tablet—Scales of Measurement—Traces of Extinct Rites, 256 CHAPTER XI. SEPULCHRAL MOUNDS. Sources of Information—Hill Mounds—The Scioto Mound—The Taylor Mound—The Issaquina Mound—The Elliot Mound—The Lockport Mound—Black Bird’s Grave—Scioto Valley Mounds—Symbolical Rites—Human Sacrifices—The Grave Creek Mound—Common Sepulchres—Cremation—Scioto Mound Cranium—Sacred Festivals, 277 CHAPTER XII. SACRIFICIAL MOUNDS. Mound Altars—Altar Deposits—Quenching the Altar Fires—Mound Hearths—Mound City—Military Altar Mounds—Their Structure and Contents—Significance of their Deposits—Analogous Indian Rites—Transitional Civilisation, 293 CHAPTER XIII. SYMBOLIC MOUNDS. The Wisconsin Region—Animal Mounds—Symbolic Mounds—Big Elephant Mound—Dade County Mounds—Magnitude of Earthworks—Enclosed Works of Art—Rock River Works—The Northern Aztalan—Ancient Garden Beds—The Wisconsin Plains—A Sacred Neutral Land—The Alligator Mound—The Great Serpent, Ohio—Serpent Symbols—Intaglio Earthworks—Suggestive Inferences—The Ancient Race—A Sacerdotal Caste—Antiquity of the Race—Inferiority of the Indian Tribes, 303