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ARCHAEOLOGY: N. C. NELSON 
ment; and, in addition, an untold number of minor ruins, partly of the ran- 
cheria type, scattered over both the Central area and the great Marginal zone. 
The immediate problem confronting the archaeologist has been to decide whether 
these ruins were chronologically separable. Until recently the general verdict 
has been that they were not, except of course within the narrow hmits of 'his- 
toric' and 'prehistoric' A third and intermediary group we may perhaps con- 
cede to have been detached on the basis of traditional references to it, but that 
is all. Our prehistoric ruins were simply 'prehistoric,' that is, roughly speak- 
ing, they were of the same age: and the result has been some extraordinary 
speculations about great numbers of peoples and their mysterious disappear- 
ance, which has finally been credited by some to a fancied 'change of climate. ' 
Unfortunately, the appearance of the ruins was no criterion of age. Neither 
did the achitecture as architecture give away in a really clear manner the order 
of development, doubtless partly because architecture is in a large measure 
determined by environmental conditions. Pottery — an ever present accom- 
paniment of the ruins — is on the other hand, an exceedingly plastic phenome- 
non, varying from place to place and from time to time, in response to the in- 
ventive faculty, far more readily than does architecture. We may therefore 
decide the relative age of any given ruin by determining the age of the particu- 
lar style of pottery which it exhibits; and this latter feat is easily accomphshed. 
We have but to find the stratigraphic position of this particular style in the 
total series of styles as they occur in refuse heaps or in actually superposed 
ruins. Sometimes the stratigraphic position has to be determined without dig- 
ging into the refuse heaps — there being none, but the principle involved is the 
same: we have to begin with the style of ware lying on top or still in use and 
must work back or down through the series until we arrive at the bottommost 
style, which is the oldest. We may indicate our general procedure therefore 
by saying that instead of as formerly hunting out the most picturesque ruins 
for excavation or at any rate the ruins giving promise of the finest outlay of 
specimens, we have begun commonly with the despised ruins of historic date 
situated in the heart of the present Pueblo habitat. 
Results to Date. — Our method has not yet been apphed to the entire Pueblo 
area and consequently our results are not complete in respect to numerous de- 
tails. Nevertheless, the general outline of things, i.e., the chronological dis- 
position of the ruins, is already tolerably clear and has been diagrammatically 
represented in figure 2 which is, as it were, a section in the A-B fine of figure 1. 
To date we have, so to speak, dug down through the superposed culture levels 
found in both the Zuni and the Tewa circles, in fact through several additional 
but more ancient circles not presented in the diagram. By thus discovering 
the time order of things we have with the same effort discovered the key to the 
whole spatial arrangement. For as we dig down through the vertical series 
we pass gradually from Pueblo to Rancheria traits and from Rancheria to 
Nomadic traits exactly as if we were traveling from the present center of Pueblo 
life out over the various zones to the Nomadic border. Briefly, it is archaeolog- 
