Recent excavations in the Southwest have revealed a succession of stages as regards buildings. The first houses in this region may have been thatched or earth-roofed. The earliest in which stone was used were small, dug out a few feet, the sides of the excavation lined with, upright rock slabs, and a superstructure of poles or mud-filled wattling added. Then followed a period of detached one-room houses, with rectangular walls of masonry; and finally the stage of drawing these together in clusters and raising them in terraced stories. This whole development can be traced within the area. Yet it by no means follows that it originated wholly within the area. The knowledge of laying stone in courses, the impulse or habit of doing so, might, theoretically, just as well have come from without; and evidently did actually come into the Southwest from Mexico.
This is a type of situation frequently encountered in culture history problems. A group of data seem to point to a spontaneous origin on the spot so long as they are viewed only locally, whereas a broader perspective at once reveals them as merely part of a development whose ultimate source usually lies far away. For instance, the backward Igorot tribes of the interior Philippines rear imposing terraces for their rice plots; their more advanced coastal neighbors do not. It has therefore been debated whether the Igorot invented this large-scaled terracing or learned it from the Chinese. Yet the terracing is only an incident to rice culture, which is widespread in the Orient, ancient, and evidently of mainland origin. The knowledge of terracing was therefore no doubt long ago imported into the Philippines along with rice cultivation, and the Igorot only added the special local development of carrying the terraces to a more impressive height. There is no question that the increase and better concatenation of knowledge is gradually leading to more and more certain instances of wide diffusions and fewer and fewer cases of independent origin.
Town life possesses a material aspect—that of the type and arrangement of dwellings—as well as the social and political aspects already touched on. The largest towns in America were those of Mexico and Peru, whose capitals may have attained populations of fifty to a hundred thousand. The Maya towns were smaller, in keeping with the Maya failure to develop an empire. The largest towns of the Chibcha of Colombia may have held ten or twenty thousand souls. The most flourishing pueblos of the Southwest seem never to have exceeded three thousand inhabitants. The Calchaqui towns in Andean Argentina were no larger, probably smaller. Southeastern and Northwest Coast towns ran to hundreds instead of thousands of population. These figures tell the usual story of thinning away from center to peripheries.
But local differences were sometimes significant. The Southeastern town, except for its court and rude public buildings, was straggling and semi-rural compared with the compact, storied, and alleyed Southwestern pueblo; often it was less populous. Yet its political and military development was more advanced, at any rate as a unit in the larger group of the confederacy.
196. Metallurgy
The use of metals in America falls into three stages. The peripheral and backward areas, such as Patagonia and California, and those parts of the Tropical Forest in which nature had denied a supply and remoteness had shut off trade, did wholly without metals.
In the areas of medium advancement, like the Northwest, Southwest, and the ancient Mound Builder region of the Ohio Valley, native copper was beaten out into sheets, trimmed, bent, gouged, and engraved. It was not smelted from ore nor cast. Its treatment was thus essentially by stone age processes. Gold, silver, and other metals were not used; iron only sporadically when it could be obtained in the native metallic state from a fallen meteorite. The supply even of copper was rarely large. It flowed in trade, much like precious stones among ourselves, to the wealthier groups of nations able to part with their own products in exchange for this substance prized by them for jewelry and insignia but rarely made into tools.
The third stage is that of true metallurgical processes, and is confined to the three Middle American areas. Here, copper, gold, silver, and so far as they were available tin and platinum, were sought after and worked. Copper at any rate was extracted from its ores by smelting; all the known metals were fused and cast, both in permanent molds and by the method of melting wax out of a single-time mold. Wire was beaten or drawn out; gold leaf and acid plating practised; and welding, hardening by hammering, and self-soldering were known. Alloys were made: copper-tin bronze in Bolivia and the south Peruvian highland, whence its use later spread north, perhaps being carried as far as Mexico (§ [108]); copper-arsenic bronze and copper-silver alloy on the Peruvian coast; copper-gold in Colombia and Mexico; copper-lead bronze in Mexico.
Nowhere, however, was metal the standard material for tools, which continued to be mostly of stone or wood. Metallic tools and utensils, especially knives and axes, were not altogether rare in the bronze region of South America. The superior hardness of bronze as compared with copper no doubt proved a stimulus in this direction. But Maya temple-cities were built with stone tools, and the Aztecs cut and fought with obsidian. In general, metal remained treasure or ornament. There were not even the beginnings of an iron culture anywhere in the hemisphere.
In the larger outlines, the history of American metallurgy is thus simple enough, as something developed late and never diffused beyond the central region of intensive culture. As to the sequence of use of the several metals and processes, on the other hand, rather little has been ascertained. It seems that in these matters South America might have been somewhat in advance of Mexico, both in time and in degree of attainments. The age of the metallurgical arts in Middle America must not be underestimated. In spite of their relative recency, they can hardly have been less than several thousand years old.