After deliberation I concluded to describe the implements, ornaments, and utensils of North America according to class or type rather than by locality. The several scholars who had aided me in this work and to whom I am under the greatest of obligations are therefore given credit in their several places. This was a better plan, and all of my observations are so grouped. I am especially indebted to Mr. Charles E. Brown, Secretary and Curator of the Wisconsin Archæological Society and at present Dean of the State Historical Museum at Madison, Wisconsin; and to Professor Henry Montgomery, Ph.D., Head Curator of the New Museum of the University of Toronto, Ontario. Both of these gentlemen are co-laborers in the preparation of the pages which follow; both have offered suggestions and been of great assistance; both made thorough studies in their respective regions. Mr. Brown’s papers in the _Wisconsin Archeologist_ and other reports, and his studies in museums in the Northwest, have made him an authority on copper and other forms of ancient objects. Professor Montgomery has carried on investigations, extending through many years, of the archæology of the Dakotas, Utah, and eastern and central Canada. Readers will observe that I have embodied Mr. Brown’s papers in various portions of “The Stone Age” according to the types under discussion, but Professor Montgomery’s several papers are presented as geographical treatises in Volume II, just before my own Conclusions. Much credit is due to both of these scholars for their permission to make use of previously published papers, and for hearty coöperation. I am under obligations to the Wisconsin Archæological Society for the loan of plates illustrating specimens in its collection, and to Mr. George A. West, the authority on Wisconsin pipes, for the loan of figures illustrating pipes from the Northwest; and, further, to Mr. West for his kindness in reading my chapter on pipes and offering suggestions. The Directors of the Milwaukee Public Museum have my thanks for their generous action in making, especially for “The Stone Age,” a series of plates illustrating type-specimens in copper on exhibition in their collection. Dr. S. A. Barrett, Curator of Anthropology in the Milwaukee Public Museum, also rendered me assistance. Dr. George L. Collie, Curator of the Logan Museum, Beloit, Wisconsin, kindly made for me a number of plates of interesting copper objects, striated axes, and other artifacts in his museum. He also furnished me with descriptions, and permitted me to republish portions of his paper entitled “Aboriginal Discrimination in the Selection of Material for Tools,” printed in volume VII, number 3, of the _Wisconsin Archeologist_. These and other gentlemen have been very kind to me and I appreciate their coöperation. That “The Stone Age” may be a success is largely due to the interest taken in it by my numerous correspondents.