Finish.—The finish, as compared with the work of civilized nations, is rude. The surface is often simply hand or trowel smoothed. Generally, however, it was more or less carefully polished by rubbing with an implement of stone, shell, bone, or other suitable substance, the markings of these tools being distinctly visible. Nothing resembling a glaze has been found on pieces known to be ancient. The surface was sometimes washed or coated with a slip or film of fine clay which facilitated the polishing, and in very many cases a coat of thick red ocher was applied.
Ornament.—The ancient potter of the middle province has taken especial delight in the embellishment of his wares, and the devices used are varied and interesting. They include, first, fanciful modifications of form; second, relief ornament; third, intaglio figures; and, fourth, designs in color.
Modification of shape.—It can hardly be claimed that the ancient peoples of this region had a very refined appreciation of elegance of outline, yet the simple, essential forms of cups and pots were by no means satisfactory to them. There are many modifications of shape that indicate a taste for higher types of beauty, and a constant attempt to realize them. The æsthetic sentiment was considerably developed.
There is also a decided tendency toward the grotesque. To such an extreme have the dictates of fancy been followed, in this respect, that utility, the true office of the utensil, has often taken a secondary place, although it is never lost sight of entirely. Bowls have been fashioned into the shapes of birds, fishes, and reptiles, and vases and bottles into a multitude of animal and vegetable forms without apparent regard to convenience. All of these modifications of essential forms were doubtless looked upon as, in a sense, ornamental. So far as I can determine they were in no case intended to be humorous.
Relief ornament.—Decorative ideas of a purely conventional character are often worked out in both low and salient relief. This is generally accomplished by the addition of nodes and fillets of clay to the plain surfaces of the vessel. Fillets are applied in various ways over the body, forming horizontal, oblique, and vertical bands or ribs. When placed about the rim or base, these fillets are often indented with the finger or an implement in a way to imitate, rudely, a heavy twisted cord—a feature evidently borrowed from basketry. Nodes are likewise attached in various ways to the neck and body of the vessel. In some cases the entire surface of the larger vessels is varied by pinching up small bits of the clay between the nails of the fingers and thumb. An implement is sometimes used to produce a similar result.
Intaglio designs.—The æsthetic tendencies of these potters are well shown by their essays in engraving. They worked with points upon both the plastic and the sun-dried clay, as well as at times upon the fire-baked surface. Figures thus produced exhibit a wide range of artistic achievement. They illustrate all stages of progress from the most archaic type of ornament—the use of dots and straight lines—to the most elegant combinations of curves; and, finally, to the delineation of life forms and fanciful conceptions.
Generally, when a blunt implement is employed, the line is produced by a movement that I shall call trailing, in contradistinction to incision, in which a sharp point is used, and excision or excavation, which is more easily accomplished with the end of a hollow reed or bone. Impressed or stamped ornament is of rare occurrence, and anything like repoussée work is practically unknown. The practice of impressing cords and fabrics was common among many of the northern tribes, and nets have been used in the manufacture and ornamentation of vases at many points within this province. The use of stamps, especially prepared, was in vogue in most of the Gulf States, and to a limited extent in northern localities.
Designs in color.—The colors used in painting are white, red, brown, and black, and have generally consisted of thick, opaque, clayey paste, white or colored with ochers. Occasionally the colors used seem to have been mere stains. All were probably laid on with coarse brushes of hair, feathers, or vegetable fiber. The figures are in most cases simple, and are applied in broad, bold lines, indicative of a strong talent for decoration. The forms are, to a great extent, curvilinear, and embrace meanders, scrolls, circles, and combinations and groupings of curved lines in great variety. Of rectilinear forms, lozenges, guilloches, zigzags, and checkers are best known.
The decided prevalence of curved forms is worthy of remark. With all their fertility of invention, the inhabitants of this valley seem never to have achieved the rectangular linked meander, or anything more nearly approaching it than the current scroll or the angular guilloche, while other peoples, such as the Pueblos of the Southwest and the ancient nations of Mexico and Peru found in it a chief resource. The reasons for this, as well as for other peculiarities of the decorative art of the mound-builders as embodied in pottery, must be sought for in the antecedent and coëxistent arts of these tribes. These peoples were certainly not highly accomplished in the textile arts, nor had they felt the influence of advanced architecture such as that of Mexico. The influence of such arts inevitably gives rise to angular geometric figures. Taken as a whole, the remains of the mound-builders would seem to point to a hyperborean origin for both the people and their arts.