SECTIONAL TRANSACTIONS.— E. 379 



the Rio Chama drainage and a south-easterly continuation into the Arroyo 

 de Pecos. According to the archaeological work of H. P. Mera and the 

 dendro-chronological studies of W. S. Stallings, the time concerned falls 

 within the fourteenth, fifteenth and sixteenth centuries a.d. The main 

 determinant of the settlements studied is a pottery development (Biscuit 

 wares) characteristic of the whole area and indicative of a certain cultural 

 and economic unity. The evidence suggests that Biscuit wares developed 

 in a loosely knit assembly of settlements within a fairly well defined 

 geographical unit— a unit small enough to produce a certain uniformity, 

 large enough to permit local variations. It further suggests the temporary 

 characterisation of a small geographical area within the larger framework 

 of the agricultural peoples of the south-west. 



Human occupation, based on the marginal cultivation of maize, beans 

 and squash on the bottom lands, low terraces and alluvial fans, was rendered 

 still more hazardous by the absence of domesticated animals and birds, with 

 the exception of the dog and the turkey. Hunting and collecting are 

 correspondingly important, although the former was limited in range and 

 efficiency by the absence of the horse. Thus sevei-al early sites are near the 

 junction of the piiion zone (piiion seeds) and the yellow pine zone (deer, 

 bear, mountain sheep). Maps of the distribution of settlements at the close 

 of the fourteenth, fifteenth and sixteenth centuries a.d. indicate the following 

 sequence of events. 



In the fourteenth century there were 56 comparatively small villages, 

 but during the course of the century there was a general withdrawal from 

 peripheral areas and a concentration upon the better terrace and bottom 

 lands. Such concentration resulted in fewer but larger villages. Con- 

 siderable shrinkage had taken place by the beginning of the seventeenth 

 century, the number of villages having dwindled to 13. The reasons are 

 difficult to assess. Coronado's expedition had come and gone, leaving 

 unsettled conditions in its wake ; marauding nomads may have been exerting 

 increasing pressure ; between 1558 and 1593 there was an abundance of 

 drought years, culminating in the particularly intense drought of 1579-85. 



Mr. A. E. Smailes. — Population changes in the colliery districts of North- 

 umberland and Durham since 1801 (12.15). 



Based upon the parish returns of the Census Reports since the first 

 Census (1801), a detailed study of population changes in these colliery 

 districts, where coal-mining is the predominant occupation, reveals the 

 process of mining colonisation and the characteristics of the population 

 cycles of mining communities . 



The history of settlement has been far from uniform over the coal-field, 

 and has been characterised throughout its course by short-distance migra- 

 tions from stagnating or declining to new or developing districts. After 

 about 1830, moreover, many districts experienced large-scale immigration 

 from outside : more recently, however, migration from the coal-field has 

 been taking place, and in most districts the population is at present stationary 

 or decreasing. 



The marked regional variations which are indicated in the date of com- 

 mencement of the industrial cycle, and in the number of cycles experienced 

 and their relation to each other, are seen to be related ultimately to the 

 geology as it affects the coal resources and their accessibility, to the distribu- 

 tion of different types of coal and the development of their respective 

 markets, and to situation in relation to transport facilities. 



They are in turn reflected in differences in the pattern and type of mining 



