ERUPTION OF THE SOUFRIERE IN ST. VINCENT. 321 



The etfec't of even comparatively small rido-es in detleetin<i' the }>last 

 and pi'otectino- the country ))ehind them is still moi'c noticeable near 

 Chateaubelair. Between the rivers Wallibu and Richmond there i.s a 

 high diA'iding- ridg-e. The northern valley (the Wallihu) is tilled with 

 ash and utterl}* burnt up, that to the south (Richmond Valley) is in 

 large part green. One side of the dividing ridge is blasted; on the 

 other the arrowroot is again putting out its green leaves. Another 

 ridge separates Richmond Valley from Chateaubelaii'. This ridge has 

 been in many places scorched, but the country ])ehind it has been per- 

 fectly protected, and, though co^'ered with the rain of ash, has resumed 

 its normal ap[)earance. There can l)e little doubt these ridges served 

 to direct the path and intercept the vioknce of the hot blast. 



For some days after the eruption no rain fell, and the first to visit 

 the district were able to observe the eflt'ects of the eruption unmoditied 

 by the erosive action of ruiming water. But on May 25 5:f inches of 

 rain fell. On the previous day the rainfall had l)een 2^ inches, and 

 the rainy season now set in in earnest. The effect of these deluges 

 acting on loose material lying on steep slopes was phenomenal, and by 

 the time we reached the island the surface of the sheets of ash had 

 been sculptui'ed into innumerable furrows and runnels. They cut 

 down through the incoherent sand to the layer of burnt vegetation on 

 the old soil beneath, or even into this, forming new channels, which 

 varied from a few inches to many feet in depth. To one fresh from a 

 temperate climate and unaccustomed to the power of tropical rains the 

 rapidity of denudation under these conditions was astounding. On 

 the upper part of the Soufriere beautiful feather patterns of rain rills 

 converging toward a central main axis everywhere characterized the 

 surface. The knife edges between the valleys were the only parts 

 retaining the original smooth surface, and they formed excellent 

 paths, as the sand was firm, except near the siunmit of the hill. 



On the windward s'ide of St. Vincent so much material is b(Mng 

 swept into the sea by the streams that the coast is covei-ed with black 

 sand, and near Overland Village it is possible to walk for a mile 

 beneath the sea cliffs on a broad, sandy beach, where formerly the 

 heavy surf of a weather shore beat against their base. In the arrow- 

 root fields the original surface is often to a large extent uncovered, 

 and on the upper slopes of the Soufriere there are man}^ places where 

 none of the new ash is left, but the bare surface of the old rocks is 

 everywhere exposed to view. After a heavy tropical shower valleys 

 which are usually dry may be filled with a thundering torrent several 

 feet deep and 20 or HO feet across. Under these circumstances it will 

 easily he understood that ali'cady many of the streams have thoroughly 

 cleaned out the ash from the upper parts of their channels where the 

 gradient is steepest. 



But when sucli a torrent reaches the lower valleys, which have l)een 

 filled with thick masses of hot sand, a strange conflict between tire and 

 SM 1902 21 



