The wheel was unknown in both hemispheres, and in both the manipulation of clay was by hand. True, in the Western Hemisphere there was greater dexterity and a greater number of methods employed. For example, the vase might be built up with clay inside a basket, which served to give both form and decoration; it was coiled, the damp clay being made in a string and so built up by a circular movement, drawing the side in or out as the string of clay was laid thereon, until it reached the top; it may have been decorated by the pressure of a textile fabric, real or simulated, into the damp clay. A few years ago it would have been true to have said that pottery decorated in this manner was peculiar to the Western Hemisphere, and that it had never been found in the Eastern Hemisphere, but Prince Poutjatine has lately found on his property, Bologoje, in the province of Novgorod, midway between Moscow and St. Petersburg, many pieces of prehistoric pottery which bear evidence of having been made in this manner, and while it may be rare in the Eastern Hemisphere, it is similar in these respects to thousands of pieces of prehistoric pottery in North America. One of the great puzzles for archæologists has been the prehistoric jade implements found in both countries. The raw material of which these were made has never been found in sufficient quantities to justify anyone in saying that it is indigenous to one hemisphere and not to the other. It may have been found in either hemisphere and exported to the other. But of this we have no evidence except the discovery in both of implements made of the same material. This material is dense and hard. It is extremely difficult to work, yet the operations of sawing, drilling, carving, and polishing appear to have been conducted in both hemispheres with such similarity as that the result is practically the same. Prehistoric flint-chipping was also carried on in both hemispheres with such similarity of results, even when performing the most difficult and delicate operations, as to convince one that there must have been some communication between the two peoples who performed them. The bow and arrow is fairly good evidence of prehistoric migration, because of the singularities of the form and the intricacies of the machinery, and because it is probably the earliest specimen of a machine of two separate parts, by the use of which a missile could be sent at a greater distance and with greater force than if thrown by hand. It is possible that the sling was invented as early as the bow and arrow, although both were prehistoric and their origin unknown.