5io 



POPULAR SCIENCE MONTHLY. 



cupied by Pyramid Lake the springs were more numerous and the water 

 consequently more richly impregnated with lime. As a result, we find 

 to-day in and about this lake the most interesting and remarkable tufa 

 deposits known in all the Great Basin. 



The tufa deposits are of various sorts and appearances, the differ- 

 ences being due to changes in the chemical properties of the water at 

 various stages. Some of the forms are merely encrusting, and appar- 

 ently structureless. Others show beautiful dendritic and interlacing fig- 

 ures, lapping over each other like the successive branches of some 

 organic growth. The great deposits in Pyramid Lake have been built up 

 in the form of towers, domes and pinnacles. The smaller ones bear a 

 mosl striking resemblance to great thick mushrooms with a concentric 



Fir,. 5. Tufa Homes, East shore of Pyramid Lake. Mushroom-like Form. 



structure. These mushroom-like growths start from some projecting 

 point or pebble and increase in size by precipitation from the surround- 

 ing water, until, massing together, the great domes and pinnacles have 

 been built up, rising hundreds of feet in the air. 



While these deposits are still being formed in Pyramid Lake, the 



large ones which rise so picturesquely from the water must, of course, 



have been formed before Lake Lahonton had entirely disappeared, and 



it has been only through the continued recession of the water that the 



■ -its have become exposed to our observation. 



Following the road northward along the wesl side of the lake, we 

 3 many curious forms assumed by the tufa. Here is one upon a pro- 



