486 SMITH. 



Siilu Islands, appear on either side of the trial and Moro dwellings, with 

 several small haystacks near by could be seen from time to time. How- 

 ever, large tracts of fallow land exist along the route. 



The soil everywhere is the same, for a blanket of basalt apparently lies 

 over the whole island. At Maden Patung, about a mile and a half from 

 the Sultan's house at Maymbung, are some outcrops of tuff, the only 

 sedimentary formation I saw while on the Island of Sulu. 



We reached Majanbung late in the afternoon and the next day returned 

 to Jolo by the same route we had come by, our stay being cut short by 

 the consideration that a geological reconnaissance conducted under guard 

 in a very unsettled country does not warrant the expense and the addi- 

 tional detail of men. "Such work is really more exciting than profitable." 



Several short excursions in the vicinity of Jolo were made for the 

 purpose of finding water-bearing strata, but in this respect the result 

 was disappointing. However, some splendid examples of old, worn-down 

 craters were seen. Several low, circular and apparently flat-topped hills 

 lie at a distance of 3 to 5 kilometers southwest of Asturias. They very 

 much resemble overturned saucers. The tops of these hills usually show 

 a more or less marked depression, a remnant of the old crater, and two 

 of these were inhabited by several families, with substantial houses and 

 well-kept gardens. These people live in such situations, not so much 

 because the soil is particularly rich, because it would be hard to find soil 

 more fertile than that on the lower volcanic slopes, but undoubtedly 

 because of the protection aiforded by the hills, the comparative difSculty 

 of access and the excellent lookout over all approaching trails. There is 

 usually some water either in the central depression or at the bases of these 

 volcanic mesas. 



OTHEE ISLANDS OF THE SULU GROUP. 



I returned to Zamboanga after this brief visit to Sulu and reshipped 

 on a small Constabulary paymaster-boat for the more distant islands of 

 the Sulu group. The first stopping place was at the Island of Bongao. 

 Tawi-Tawi was not visited, such observations as were possible being made 

 while sailing near to the coast. It is not a very rugged island, everywhere 

 showing gentle curves. 



Bongao is a small village and Constabulary station on the island of 

 that name, separated by a narrow channel from the southwestern end of 

 Tawi-Tawi. Coral reefs are found everywhere in these waters, so that 

 great care in navigation is necessary. Moi^nt Vigia, visible from the dock 

 (see Plate XIV), is a mass of very resistant conglomerate, 370 meters 

 high, and on a clear day the low coast of Borneo can be seen from this 

 peak. 



Some raised beaches exist in tliis vicinity and a number of fossils of 

 recent age, clearlv Pleistocene, were procured. 



From Bongao we navigated through a lab3Tinth of islands along chan- 

 nels so narrow as to make it almost possible to lean over the side of tlie 



