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SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 66 



It was found that algal growth was everywhere present when the 

 temperature of the waters was from 70° to not much above 180° 

 Fahrenheit, and that this growth had a marked effect upon the 



Fig. 17. — Three of the Seven Sisters Hot Springs above lllack Warrior 

 Geyser, one mile northeast of Great Fountain Geyser. These springs, ahhough 

 very beautiful and each of a different color, are rarely visited by tourists, and 

 the same is true of most of the Great Fountain group. Photograph by Walcott. 



aiuount and character of both calcareous and siliceous deposits. Some 

 of these are shown in the accompanying illustrations. 



