of their shape and size, were clearly pointed out by experience. And there must have been a gain in the process to such an inventive tribe. No more were long searches for properly-sized stones necessary. By means of harder stones others were chipped and shaped, and so much time was gained from looking for stones and devoted to obtaining food. And tribes using artificially-shaped stones must have had a superiority over those who relied on what natural stones they found at the moment. They stood in less danger of starvation. In the absence of other remains, the presence of roughly-fashioned stones will be the earliest reliable trace we shall find of the existence of men. In Europe such stones have been found and described by several observers. In North America we owe their discovery to the zeal of Dr. C. C. Abbott, aided in funds for excavation by the Peabody Museum of Archaeology, of Cambridge, Massachusetts. The rough stone implements discovered by Dr. Abbott in New Jersey are chipped so as to form an irregular cutting edge. They are flattened on the under side and broken to an edge from the upper. The material itself is basalt, a common kind of mixed rock of compact texture. As we find them, the surface is slightly rusted, from the particles of iron in the stone. This kind of rock is common, and the tunnel of the Erie Railway at Jersey City is cut through stone of this kind. North American rough-stone implements vary little in size and pattern, although, when we examine all the kindred rough-stone implements of the world yet known, we see that, as a class, they become gradually more determinate in their shape and the chipping more regular; they come more into the shape of spear-heads, and, perhaps, large arrow-points. Above the rough-stone implements we find those of polished stone; a departure showing that man was no longer satisfied with his first rude fashioning of his implements. Then we find the metals; and of these copper, being more pliable, is first beaten cold and worked into shape for use. Then the process of smelting and mixing with harder metals, such as iron, came to be employed; and to-day we are doing just what man has always done, improving our tools so that we may better our condition.
Surveying the whole field gone over by scientific men in recent times, we must say that these different ages have merged gradually into one another. The age of rough-stone implements or paleolithic, the age of polished-stone implements, or neolithic, the ages of copper, bronze, and iron, have succeeded each other without the possibility of our drawing the dividing line, any more than we can say exactly when what we call the middle ages ceased and modern time came in.
Certain implements are, indeed, rough stone, and others polished, but between them are intermediate specimens, and both kinds seem to have been sometimes in use at the same moment with the same people. Again, the introduction of bits of copper in some of the earlier graves precedes the fashioning of copper axes. It is a similar
