In spite of the title, this goes all the way back to the earliest discoveries of prehistoric man and reaches the inventions of ancient civilizations only in the later stages of the investigation. Baldwin, the author of Riddles of the Past and an expert on Southwest Indians, manages to put the concept of invention into a graspable anthropological perspective as he shows what diverse cultures had in common (magic, for one thing -- also toolmaking and spinning), discusses the influence of the physical environment and isolation on various groups and presents both sides of the controversy between diffusionists and those who believe that the same discoveries were made separately many times over. What really intrigues here are the specifics -- on the three primitive methods of firemaking, the variety of cultivated cereals as opposed to the limited number of domesticated animal species, the techniques of the potter and even a design for a better mousetrap dating back to 2500 B.C. Baldwin's expertise and enthusiasm give this an edge over most such surveys -- both in the felicitous choice of examples and overall theoretical coherence.