830 



The National Geographic Magazine 



Friday, January 31, igo8 — "The Conserva- 

 tion of Our Natural Resources." Mr Gifford 

 Pinchot, Chief of the U. S. Forest Service. 



Friday, February 7, igo8 — "South Africa : 

 The Natives and the Mines." Mr Gardiner F. 

 Williams, author of "The Diamond Mines of 

 South Africa" and for many years General 

 Manager of the De Beers Diamond Mines, 

 Kimberley. Illustrated. 



Friday, February 14, 1908 — "The Deep-wrater 

 Route from Chicago to the Gulf and its Con- 

 nections." Hon. Joseph E. Ransdell, Member 

 of Congress from Louisiana and President of 

 the Rivers and Harbors Congress. 



Friday, February 21, 1908 — Hon. George 

 Shiras, 3rd, of Pittsburg, has accepted the in- 

 vitation of the National Geographic Society to 

 address the Society on some of his experiences 

 in hunting wild game with the camera. Illus- 

 trated. 



Friday, February 28, 1908 — "Holland's War 

 with the Sea." Prof. J. Howard Gore. Illus- 

 trated. 



Friday, March 6, 1908 — "The Missions of 

 California." Hon. Joseph R. Knowland, Mem- 

 ber of Congress from California. 



Friday, March 13, i9o8^"Arizona — The 

 Egypt of the New World." Mr Frederick 

 Monsen. Mr Monsen describes not only the 

 ancient ruins, but the country as it is today, 

 with its Indian tribes, Spanish-Mexican settle- 

 ments, and American towns. The wonderful 

 Snake Dance of the Hopis will be shown. 



Friday, March 20, 1908 — "Persia — Past and 

 Present." Dr A. V. Williams-Jackson, of Co- 

 lumbia University. Illustrated with unusual 

 pictures taken by Professor Jackson on exten- 

 sive journeys through the ancient kingdom. 



Friday, March 27, igo8 — "The Geography of 

 the Sea." Rear Admiral Colby M. Chester, 

 U. S. Navy. 



Friday, April 3, 1908— "Cathedrals, Mosques, 

 and Temples of the World." Hon. O. P. 

 Austin, Chief U. S. Bureau of Statistics. Il- 

 lustrated. 



LAKE CAHUILLA 



The Ancient Lake of the Colorado Desert 



AT a recent meeting of the Cosmos 

 Club of Tucson, the following 

 communication was read by Mr William 

 P. Blake, emeritus professor of geology, 

 University of Arizona. 



The ancient sheet of water which in 

 comparatively recent geologic time filled 

 the basin of the Colorado Desert, below 

 the sea-level, and left the records of its 

 occupation of the valley by deposits of 

 travertin upon its rocky shores, by lines 

 of deserted beaches, by deposits of lacus- 

 trine clays holding myriads of fossil 

 fresh-water shells, and all below the level 

 of the Gulf of California, were for the 

 first time recognized and described by 

 me, in the year 1853, in a San Francisco 

 newspaper edited by J. D. Whelpley, and 

 afterwards in the Report of Geological 

 Reconnaissance in California, 1854-5, and 

 in volume v of United States Explora- 

 tions and Surveys from the Mississippi 

 River to the Pacific Ocean. 



The outline of the lake— its length, 

 breadth, and depth — its relations to the 



Colorado River and the Gulf, its origin 

 and history, were described at that time, 

 and these descriptions and this theory of 

 origin have since been confirmed and sus- 

 tained by later explorations. 



Public attention has of late been di- 

 rected toward the region by reason of its 

 partial submergence and the destruction 

 of the salt beds at Salton, in the lowest 

 part of the valley. This new sheet of 

 water, which does not rise to the ancient 

 lake-level, is known as the "Salton Sea" 

 and is appropriately named; but this 

 name should not apply to the ancient lake 

 in its entirety, which requires a dis- 

 tinctive designation, just as, for example, 

 the ancient sheet of water of which the 

 great Salt Lake is a residue is known as 

 Lake Bonneville. 



As the original discoverer and de- 

 scriber of the ancient lake, I suggest the 

 propriety of giving it a name, and pro- 

 pose "Lake Cahuilla," Cahuilla being the 

 tribal name of the aborigines who were 

 found living in and about the valley now 

 very generally known as the Cahuilla 

 Valley and whose descendants are still 

 there. 



