488 CARL SKOTTSBERG 



ing water at least after the heavier rains. The explanation generally offered 

 is that the rocks are so porous that all the water rapidly disappears beneath 

 the surface and collects at various depths or drains off through underground chan- 

 nels, eventually reaching the sea through caves in the coast rocks. Evapora- 

 tion, stimulated by frequent and fresh winds, is considerable. Consequently, 

 the original outline of the cones and craters has been retained so that the 

 topography presents a very youthful appearance, but from this we cannot 

 conclude that the island is very much younger than other Pacific islands. Ex- 

 tensive talus formations in the craters, especially in Rano Kao, bear witness 

 of long ages of slow erosion, and the destructive w'ork of the sea is quite im- 

 pressive. Knoche suggests that the island may have been twice as large as 

 it is now. The northernmost of the parasitic cones of Katiki has been 

 worn away so that only half of it is left, and the same is the case with an- 

 other crater west of Anakena. And the small rocky islets oif the shore on 

 the south side of Rano Kao must have formed part of the southwestern head- 

 land. The volcanic forces have come to rest very long ago, and no tradition 

 exists of any kind of volcanic activity. 



The soil on the lava plains is stony and shallow, and bare rock face is 

 exposed in many places. Cracks and accumulated boulders arrest the finer 

 soil and have a more luxuriant vegetation. The soil colour varies with that of 

 the mother rock from a deep brown to red and yellow of several hues. While 

 the basalts, although they are porous and honeycombed, seem to be very hard, 

 and the boulders have sharp angles, the tufas are loose and easily disinte- 

 grated, whence follows that the slopes of the cones are covered with vegeta- 

 tion. In places a loose volcanic sand is found. Where there is sufficient soil 

 this is of good quality and quite fertile when properly cultivated, and in pre- 

 historic and early historic times extensive plantations existed, supporting a 

 population of several thousand people. The injurious effects of the strong 

 winds were lessened through the construction of enclosures. Various kinds 

 were described and figured in my » Notes », p. 13, 14. 



Insect life is very poor. Earthworms occur, but so far only an intro- 

 duced species has been discovered. 



The climate. 



The island lies in the zone of the trade winds (Mataveri, lat. 27° 10' S, 

 long. 109° 26' E) which put their stamp on the weather. As all the land is of a 

 very moderate height, there is no perceptible difference between the different 

 sides of the island, and the climate is probably very uniform all over the 

 place. The rainfall is greater on the more elevated hills. 



In 191 1, a well equipped meteorological station w^as erected in Mataveri, 

 and a smaller one on the rim of Rano Kao. Besides, there was a pluviometer 

 on Otu (Terevaca of Knoche). All these places are situated in the south- 

 west part of the island. The observations were run from May i, 191 1, to 

 April 30, 191 2, and published in the Reports of the Instituto Central Meteoro- 

 logico y Geofisico de Chile (No. 4, 191 3). The observations were continued in 



