sandbank, and finally of a shore-sand barrier. This work is being 

 actively aided and hastened by the wind, which blows the dry sand 

 inland. The constructive action of the two forces proceeds rapidly, 

 and at such places the land is gaining at the expense of the sea ; while 

 at others, as at Accra, those portions of the cliffs that are composed 

 of soft rocks are being rapidly broken down and the material washed 

 away. Shore-sand barriers in most places prevent the waters of the 

 impounded streams from flowing into the sea. In a few places, however, 

 the streams are able to discharge during the rainy season floods, or at 

 low tide, while several of the small streams and the large rivers have 

 permanent outflows. 



" The occurrence of earthquakes is evidence that the coast is not 

 yet in a state of stable equilibrium. Small shocks, recorded by a 

 seismometer at Accra, are by no means uncommon. Severe earth- 

 quakes have been experienced at various times during the last four 

 centuries. 



" The present river system of [the] two geographical divisions is 

 comparatively of recent age. The main courses of all the streams are 

 in shallow valleys, or rather channels, though most of them have 

 grades high enough to admit of rapid corrosion. The largest rivers, 

 the Volta, Prah, and Tano, have low falls and rapids near the coast ; 

 they approximate to the heights of the latest uplifts of the land. 



" The prevailing colour of the soil is red of various shades over 

 most of the country whether derived from crystalline, metamorphic, or 

 sedimentary rocks, This is apparently owing to the oxidation of iron 

 which is widely distributed in small or fair quantities through all these 

 rocks. The more recently raised portion of the coast-line consists of 

 pale grey sands with humus, while the lagoon deposits are dark blue to 

 black mud. 



" In the forest belt the thick vegetation prevents the washing 

 away of the soil as it forms from the decay and disintegration of the 

 underlying rocks. Thus is formed a thick cap of soil, ranging in some 

 places to 30 feet in thickness. In other places, under certain conditions, 

 this soil becomes cemented by iron oxide into a firm rock, broadly called 

 ' laterite,' which occurs on the tops of flat ridges or irregularly upon 

 flat expanses at high or low levels. 



3p ^ •(* "n 



" The Akwapim Range owes its orientation to its geological 

 structure, for it consists of folded schists, quartzites, phyllites and 

 sandstones, striking generally north-east to south-west. It is deeply 

 dissected along the strike of these rocks, where several streams have 

 eroded deep valleys with parallel ridges, and across the strike, where 

 small streams have cut deep valleys even through quartzites and quart- 

 schists." 



