SCENERY. 159 



Calaveras County, is a cave in which a Know-Nothing lodge 

 was accustomed to meet in 1855. In the bluff bank of the 

 Middle Fork of the Cosuinnes River, eighty feet above the 

 stream, is a cavern called Limestone Cave, with many intri- 

 cate passages and some fine stalactites. 



117. Mirage. Among the most remarkable scenes wit- 

 nessed in California are the illusions of the mirage, seen fre- 

 quently in the deserts of the Colorado and the Great Basin, 

 and sometimes as far north as San Francisco. " All the phe- 

 nomena of mirage," says Professor W. P. Blake, "are exhib- 

 ited on a grand scale upon the Colorado Desert. Mountain 

 ranges, so far distant as to be below the horizon, are made to 

 rise into view in distorted and changing outlines. Inverted 

 images of smaller objects, and apparent lakes of clear water, 

 are often seen, and invite the traveler to turn aside for refresh- 

 ment. The first exhibition of a mirage that was seen [by 

 Blake's party] was from the margin of the plain at Carriso 

 Creek, looking toward the Gila, about ninety miles distant. 

 It was early in the morning, and the eastern sky had that 

 golden hue which precedes the rising sun. Tall blue columns, 

 and the spires of churches, and overhanging precipices, seemed 

 to stand upon the verge of the plain. Their outlines were 

 changing gradually, and, as the sun rose higher, they were 

 slowly dissipated. After reaching Fort Yuma, and witnessing 

 the strangely precipitous and pinnacled outline of the moun- 

 tains beyond, it was at once apparent that the mirage con- 

 sisted of their distorted images. When we were upon the 

 northern part of the desert, the peak of Signal Mountain was 

 often distorted and raised above the horizon. The points of dis- 

 tant ranges also seemed at times to be elevated above the 

 surface, precisely as the headlands of a coast sometimes ap- 

 pear to rise above the water at sea." 



One morning in the last week of March, 1871, the people of 

 Santa Cruz looking southward towards Monterey, which is 

 twenty-two miles distant, and usually invisible, saw the town 



