744 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



was about one hundred and twenty yards long and twenty-five yards 

 broad. 



Temperature of water, 77.6° ; air, 78.G0O. 



A short distance from this was another body of water, very clear, and 

 free from foreign substances. It was nearly round, with an average 

 diameter of nearly one hundred yards. 



Temperature of water, 74° ; air, 78°. 



There were numbers of springs visited which would have been ex- 

 amined en detail but for the lack of necessary vessels for the transporta- 

 tion of samples. As before stated, some that were brought back for 

 thorough analysis contained sufficient organic matter originally so as 

 to be in a worthless condition when opened for any such purpose. In 

 others there was an accumulation of gas, either carbureted hydrogen 

 or sulphureted hydrogen, from the decomposition of foreign matter held 

 in suspension. In only a few instances were the samples fit for a quali- 

 tative analysis. There should always be sufficient chemicals and appli- 

 ances on hand in the field, so as to obtain some idea of the nature of the 

 constituents present, and to submit duplicates to critical examination, if 

 possible, at the earliest convenient time and place. 



APPENDIX C. 



NOTE ON THE RARER MINERALS FOUND IN OWENS VALLEY, CALI- 

 FORNIA. 



Blind Spring District, located in the upper end of Owens Valley, 

 furnished some beautiful examples of crystallized compounds, until the 

 mines reach a depth of over 200 feet, when water-level was reached. Be- 

 neath this, the " heavy sulphuret ores" occur, where the volatile com- 

 pounds, or those containing iodine, bromine, chlorine, antimony, or 

 arsenic, are rarely found. The latter occur above, where, through vari- 

 ous physical causes, compounds containing one or more of these elements 

 are formed. Good crystals of most minerals are scarce throughout the 

 extreme West as a rule ; but at times fine examples occur, though not in 

 abundance, excepting in a few instances. 



1. Angelsite. — Crystals half an inch in length and a quarter of an 

 inch thick have been secured in small quantities. 



2. Argentite. — Small specimens of great purity. 



3. Aziirite. — In fine masses and clusters of crystals. 



4. Cerussite. — In small but brilliant crystals. 



5. Cuprite. — In cubes 0.4 of an inch across. Brilliant and perfect. 



6. Malachite. — In small but beautiful masses. 



7. Mimetite. — Sparingly, with other compounds of lead. 



8. Minium. — Barer than the last-named. 



9. Fartzite. — Bather abundant shortly after the opening of the mines. 



