64 LAKES OF NOIITH AMERICA. 



In experimenting on the transparency of the Avaters, Professor John 

 LeConte found that a white disc 9.5 inches in diameter, when fastened to 

 a line and lowered beneath the surface, was clearly visible at a depth of 

 108 feet. It is to be remembered that the light reaching the eye in such 

 an experiment traverses through water twice the distance to which the 

 disc is submerged, or in the experiment referred to, 21(i feet. The only 

 instance in this country in which Avaters have been found to l)e more 

 transparent is in the great limestone-water springs of Florida. 



Soundings made in Lake Tahoe by LeConte, as already stated, gave a 

 maximum de})tli of 1(345 feet, but a more detailed survey may possibly 

 discover still more profound depths. Those measurements sliow that the 

 lake, with the exception of Crater lake, Oregon, is the deepest inland 

 water-body in America yet sounded, and exceeds the depth of any of the 

 lakes of Switzerland, but is not so deep as lakes ]Maggiore and Como on 

 the south side of the Alps. 



The temperature observations made in Lake Tahoe previousl}' referred 

 to, furnish an illustration of the fact that deep lakes, even when situated 

 at a high elevation and subject to low winter temperatures, do not freeze. 

 The surface waters are cooled in winter and descend, while Avarmer Avaters 

 from beloAV rise and take their place, thus establishing a circulation, but 

 the body of Avater is so great that its entire mass never becomes cooled 

 sufficiently during the comparatiA^ely short Avinters to check the upAvard 

 circulation and allow ice to form. At the greatest depth reached the 

 temperature Avas 39.2° F., Avhich is the temperature of fresh Avater at its 

 maximum density; and from more extended observation in other lakes, 

 the Avater is believed to retain this temperature throughout the year. 



Lake Tahoe is situated at such an altitude that its shores are l)leak 

 and inhospital^le during a numl)er of months each year. For this reason 

 it is probable that it Avill never be selected as a place of continued resi- 

 dence by any considerable numl)er of families, l)ut during the sunnner, 

 Avhen the adjacent vallej^s are parched by desert heat, the air in the lake- 

 filled valley is cool and bracing ; it then furnishes a charming retreat for 

 the dAvellers of the cities of the Pacific coast, as Avell as for more distant 

 Avanderers. As a place for summer rest and recreation it is second to 

 none of the popular resorts of the United States or Canada. 



The Avaters of Lake Tahoe oA^erfloAv through the Truckee canon and 

 form a bright, SAvift-floAving stream, Avhich finds its Avay to Pyramid and 

 Winnemucca lakes, situated 2400 feet lower, in the desert valleys to the 

 north. The Avaters Avhen starting on their troul)led journey are as pure 



