LETTER OF TRANSMITTAL. 
Department of the Interior, 
United States Geological Survey, 
Washington, D. G\, March 19, 1901. 
Sir: In December, 1900, specimens of tin ore were submitted to the 
Survey for examination. They proved to contain abundant cassiterite 
and wolframite in a quartz gangue. The}^ were said to come from the 
vicinity of El Paso, Texas, and in view of the infrequency of well- 
authenticated occurrences of tin ore in the United States it was judged 
wise to have their provenance and manner of occurrence verified at 
the earliest opportunity. This opportunity presented itself when, in 
January, 1901, Mr. W. H. Weed had occasion to pass through El Paso, 
and he was instructed to make a reconnaissance examination of the 
locality whence the specimens were said to come. The result of his 
examination is presented briefly in the following report, the immediate 
publication of which I recommend. 
S. F. Emmons, 
Geologist in Charge of Section of Metalliferous Ores. 
Hon. Charles D. Walcott, 
Director of United States Geological Survey. 
