68 ANNALS NEW YORK ACADEMY OF SCIENCES 



MAPS 



A hasty reconnoissance examination is seldom a satisfactory basis for 

 an areal map. This is quite trne of the present investigation. On this 

 accomit, therefore, if it M'ere not for other considerations, an areal map 

 would not be attempted. But in this case, where a good many more or 

 less independent special investigations are to be carried on in which a 

 reasonably accurate geological map will prove decidedly helpful, there is 

 sufficient excuse for presenting a reconnoissance map. An earlier map 

 of this kind prepared by E. T. Hill was made under conditions so much 

 less favorable for travel, and seems to have been constructed in some par- 

 ticulars with so much less opportunity for observing the actual conditions 

 in certain areas, that an entirely new map is believed to be the better 

 solution of the present need. The accompanying reconnoissance map is 

 intended, therefore, as a convenient guide or location map for subsequent 

 more sjDecial investigations, and it is expected to be wholly replaced by 

 one of much more detail and greater accuracy as a final product of this 

 survey. 



Acknowledgments 



The members of this expedition have appreciated the very material 

 help, the sound advice and useful suggestions given by the officials of the 

 government of Porto Rico, and are indebted to Governor Yeager for his 

 very practical aid in making arrangements for the field work and for his 

 live interest in these investigations ; to (Colonel Shanton, chief of the In- 

 sular Police, for his willingness to give introductions to men acquainted 

 with special mineral localities and for his precautions to insure protec- 

 tion against unnecessary delays ; to Mr. Wheeler, of the Interior Depart- 

 ment, for assistance in securing suitable maps as a basis for travel and 

 notes; to Mr. Bonner, the Auditor, for facilitating tlie settlement of ac- 

 counts; to Dr. Lippitt, of the Bureau of Sanitation, for information 

 regarding sanitary precautions and hotel accommodations; ami to Mr. 

 Campbell, of the Bureau of Transportation, for the excellent equipment 

 for travel which contributed largely to the success of the expedition. 



Many others have been of assistance in pointing out localities of special 

 interest, in giving names of reliable informants and in acquainting us 

 with the usages and customs of the country. 



