Each chapter of Das unbekannte Afrika is headed by small maps showing the distribution of the cultural elements treated in it. This is the form of registration which Frobenius has practiced for the last 25 years. Thus the enormous wealth of ethnological data is statistically fixed. The area, for instance, for a house type or a custom, when found in his travels, is compared with data found, in literature, on the same subject, and all the findings are, again, registered on a map. The results of seven expeditions, on which skilled artists accompanied him, have been kept under control in this manner. As soon as the center of a district which seemed of interest was reached, numerous trained assistants were sent in different directions. Each took notes and pictures on a given subject, so that a marvelous amount of work could be accomplished. Other data were gained by leaving questionnaires among the resident missionaries, merchants, or government officials, to whom letters were sent later, where matters did not seem sufficiently clear, when studied at home.
The deductions made are illustrated by the fascinating pictures contained in The unknown Africa, in which more than half of the space is devoted to illustrations. By them the interrelation between Neolithic European, Asiatic, Phoenician, Carthaginian, and the African cultures is shown, mainly in regard to art and architecture.
African art is nearer related to the prehistoric European than to the Asiatic and the American. On the whole, that of the south is historic, as compared with that of northwestern Africa. Linguistically the south African idioms are the oldest, while the illiterate eastern constitutes the second period, and the northwestern the youngest.
Racially the lighter Hamite in the northwest has displaced older types, which are now prevalent in the east. The Hamitic culture extends between the Canaries and the Indian Ocean, with extensions into Abyssinia and the southern apex. In the south dwell the Ethiopians. Originally there were two main points of cultural influx, one in Erythraea, and one on the western shores, having travelled through the Mediterranean and Gibraltar, around northwestern Africa. Some influence was also introduced from the north, and traversed the Sahara desert. There it did not survive, but penetrated the Soudan.
The two cultures are explained distinctly. The Hamitic contains remnants of the solar cult, while the Ethiopian shows that of the moon. The first has the matriarchal while the second has the patriarchal system. Hamitic inclinations are connected with the animal world, the Ethiopian with Mother Earth and the plant. Proofs for the entry of Hamitic elements by way of Erythraea are found in the fact that the matriarchate has existed on the eastern coast of India, and in southern Arabia, and that it still exists in northern Africa. Also, the ritual killing of the kings which exists near the White Nile, and in the eastern Soudan, was reported, by Diodorus, to have existed on the eastern coast of India and in Meroe.
The Nile kept Egypt in touch with the rest of the civilized world, while the western parts of northern Africa had no great stream to retain the ancient height of culture, but this tended to the guarding of traditions, and the preservation of ancient customs.
The same ritual procedure which is depicted on the rock-drawings, thousands of years old, prevails in these days in western Soudan. The same posture is taken by the supplicant huntsman, in regard to the cardinal points, while he traces similar images on the sand. The present-day pious Yoruba consults the replica of boards which were found in Ife, and which were thousands of years old. On them are carved the four main pairs of deities, or the sixteen cardinal points.
Frobenius found ancient terra-cotta heads and wood carvings which represented the same objects as those found in Benin. The latter must be considered as mediaeval. The pupils of the Benin heads are perforated, while the Ilife heads have blind eyes. This would affix, to the latter, a much greater age, as it is a feature of ancient Mediterranean sculpture. The Atlantic art of western Africa is highly developed, and has nothing in common with primitive Negro art. Some of the boards are exquisite, and rows of beautiful figures and mythological representations are carved on a door, in Yoruba, as shown in the book.
A very interesting theory is put forth, in this connection. So far, it was accepted that time, in archaeology, could be measured only by stone objects, as these were lasting. The author, however, is of the opinion that rock drawings and carvings may answer the aesthetic or ritual requirements of a region or a people for many centuries, while wooden implements and works of art must be replaced, being eminently perishable. Wood is available everywhere. The idea underlying a figure is renewed, with each generation of carvers, and the traditions are handed down as faithfully by wooden carvings as by folk-lore.