SECTIONAL TRANSACTIONS.— E. 349 



it lacks mineral wealtli, and possesses no great industries comparable in magnitude 

 ■with the textile manufactures of Bombay and Calcutta. 



The influence of climate and relief features in determining land-utilisation, and 

 hence the distribution of population and settlements (villages), are dealt with in some 

 detail. A few typical villages from different districts scattered over the area are 

 touched upon, followed by a summarv of the salient features of the village life in the 

 Tamil Nad. 



Afternoon. 



Dr. C. E. P. Brooks. — Climatic Changes in Historic Times. 



It appears probable that there have been during historic times certain periods 

 when the climate of large areas differed appreciably from that of the present century. 

 The conditions are discussed during a number of critical periods, as far as the available 

 evidence permits : — 



ca. 2200 B.C. Dry in Europe and western Asia. In western and central Europe 

 the rainfall was in places only about half the present amount. 

 800-400 B.C. Wet and stormy, especiall}' in central Europe. 

 0-200 A.D. Approaching present conditions. 

 500-800 A.D. Probably rather dry, especially in central Asia. 

 1200-1400 A.D. Wet and stormy in north-western Europe. 

 1700-1750 A.D. Dry in western Europe. 



Prof. A. E. Douglass. — Past Changes in Climate in Relation to Settlements 

 in the New World. (In Section A Room.) 



The annual rings of trees provide a means of studying certain characters of past 

 climates. In the south-western parts of the United States showing an annual rainfall 

 of 15 to 25 inches, the rings of the Pinns ponderosa give a very effective record of 

 rainfall variations from year to year, increased growth accompanying increased 

 rainfall. Long series of such ring values have been studied and variations have been 

 found related to the eleven-year sunspot cycle. 



Since, in the region referred to, the climate is fairly constant over a large area, 

 annual characters in rings may be traced over an extended forest district and thus 

 exact dates may be carried from tree to tree. For example, we can pass from the 

 older central part of a living tree to the outer part of an old building beam in a village 

 one hundred miles away, and then from the central part of the latter beam to the 

 outer part of, perhaps, a log from a distant prehistoric ruin. Thus, a chronologj' of 

 rings and rainfall has been carried back to a.d. 700. But this exact dating of the 

 rings gives also the actual years of cutting the logs provided the outermost rings are 

 still present. Thus, in return for providing material for building a climatic history 

 the archaeologists have received the building dates of some forty prehistoric ruins. 

 The oldest and the largest of the ruins so far dated, is Pueblo Bonito (New Mexico) 

 whose construction period extended from 919 to 1127 a.d. The method can be 

 successfully applied in many parts of the world, but not necessarily in all. 



Tuesday, September 9. 



Discussion (Sections C, E, H) on The Relations between past Pluvial and 

 Glacial Periods. (See programme of Section H.) 



Afternoon. 



Excursion to the Avon Gorge, Blaise Castle and the Aust, for the Cliff 

 section. 



Wednesday, September 10. 



Prof. Ll. Rodwell Jones. — Physical Factors concerned in the characteristic 

 Functioning of the Port of London during the Period 1800 to the Present 

 Day. 



This paper deals with the tidal and channel conditions of the Thames estuary, as 

 these affected shipping throughout the nineteenth century. 



