108 SECTIONAL ADDRESSES 
and others, who appear to have been forced thither by the Awemba or 
others from the west and the Ngoni raiders, of Zulu stock, from the east ; 
while the low Zambezi valley is peopled by numerous debilitated tribal 
fragments. 
EXTERNAL INFLUENCES. 
The effect of European influence upon the economic and social structure 
of native society in Northern Rhodesia has recently been very thoroughly 
dealt with by Mr. Merle Davis in the work already referred to. It is, of 
course, not a geographical work, though geographical factors are recognised 
by the author. I have therefore attempted to make an estimate, based 
upon our District reports, of the nature and degree of external influence 
upon the material life of the natives. These influences differ widely in 
date and in potency. The acquisition of the chief cultivated plants and 
domestic animals reaches far back, and I do not propose to deal with this. 
Direct contact with the earlier Portuguese traders has been of little account, 
save possibly in the Feira District, but in the west their indirect influence 
has been considerable in view of the migration of tribes whose ancestors 
had been in touch with the Portuguese on the Atlantic seaboard. The 
use of manioc bears witness to this, and the square or oblong type of 
house which to-day prevails in the two north-western districts probably 
derives ultimately from this source. In Balovale it replaced a beehive 
grass hut, and its superiority over the circular pole and thatch hut of the 
other Rhodesian areas is being recognised, as is the skill of its builders, 
who are often paid to build houses for neighbouring tribes. Since 1917, 
the new wave of immigrants from Angola has led to the spread of this 
house type throughout the upper Zambezi basin. 
About the southern end of Lake Tanganyika there are evidences of 
various effects of the incursions of Arab slave raiders. Here again a 
square house is found mingled with the circular huts (Abercorn), while 
the small groups of Swahili people have groves of date palms and other 
cultivated fruit trees. 
But these aspects are all insignificant in comparison with the potent 
influences due to the British rule and partial settlement by European 
farmers, the rapid exploitation of minerals in the Belgian Katanga and 
the Ndola and Broken Hill Districts of the Protectorate ; while the estab- 
lishment of missions throughout Rhodesia has had widespread material 
as well as moral effect. As indexes of the outward evidence of this 
permeation, which really amounts almost to revolution, I select data of 
three types: first, the distribution of houses built on the European 
pattern ; secondly, the continuance or otherwise of the old-established 
native iron industry ; thirdly, the direction and volume of movement of 
native labour to work for Europeans. 
Houses built on the European model, either of wood or of sun-dried 
brick, are most numerous along the southern half of the railway ; in Kalomo 
they are estimated at 10 per cent. Here also native iron-working is either 
not mentioned or is stated to have died out, or else the smiths have turned 
their attention from axes, hoes and spears to the repairing of ploughs and 
1 Cf. Fig. 3. 
