Surveying the Philippine Islands 



439 



triangulation signal with its wide, out- 

 spreading legs still on it ; they were 

 industriously cutting a wide path 

 through the thicket so as to be able to 

 produce this suspicious object intact, 

 evidently believing it a beacon of the 

 insurrectos. They were persuaded to 

 carry it up the hill again. 



The development of the field work 

 has necessarily been controlled by vari- 

 ous conditions, and it has been extended 

 along the lines which appeared most 

 feasible with the means available and 

 most likely to yield re- 

 sults of immediate use- 

 fulness. 



The wide extension by 

 the Signal Corps of the 

 telegraph system for mil- 

 itary purposes suggested 

 the determination of base 

 positions, including tele- 

 graphic longitudes and 

 zenith telescope latitudes. 

 It was fortunate that this 

 work was carried out 

 promptly, as with the 

 passing of military neces- 

 sity many lines have been 

 abandoned. Thirty-six 

 latitudes and thirty-six 

 differences of longitude 

 have been determined, 

 the points being fairly 

 well distributed over the 

 archipelago from the 

 north coast of Luzon to Zamboanga. 

 These stations have all been marked 

 and described for future reference. At 

 most stations a meridian has been laid 

 out or an azimuth measured, and mag- 

 netic observations have generally been 

 made. 



The surveying steamer Pathfinder, 

 under command of J. J. Gilbert, assist- 

 ant, U. S. Coast and Geodetic Survey, 

 arrived at Manila from Alaska in No- 

 vember, 1 901, and has since been con- 

 tinuously at work in the islands, except 

 during intervals when docking or repair 

 work on the vessel has been required. 



Harbor surveys at Cebu, Ormoc, and 

 Romblon have been made, and during 

 the past year this vessel has completed 

 important surveys of San Bernardino 

 Strait and Albay Gulf, and of San 

 Pedro Bay and the south coast of Samar, 

 as well as a thorough examination of 

 the much- used passage southwest of 

 Leyte, where a danger had been re- 

 ported. The Pathfinder is a well- 

 equipped, modern survey ship, and 

 carries two steam launches. 



A small wooden steamer was pur- 



U. S. Coast and Geodetic Steamer Pathfinder 



chased in Manila and adapted to survey 

 work. This vessel, the Research, has 

 made a number of harbor surveys on 

 the west and southeast coasts of Luzon 

 and on Mindoro and Culion islands, and 

 is at present working on the coast of 

 Negros. 



Chartered launches have been em- 

 ployed in some cases for hydrographic 

 work, and the survey of Lingayen 

 Gulf by this means has recently been 

 completed. Harbor surveys have been 

 made at a number of other places, using 

 various means. 



The abrupt coral reefs along many of 



