70 



THE SAND STRAND FLOBA 



cause of this to be minute coal particles, brought down from the at- 

 mosphere by the rain. The origin of this coal dust is, no doubt, the 

 smoke from the factories of the city, which settles all over the neigh- 

 borhood, but is nowhere so easily perceptible to the eye as on the white 

 sand surface. 



The salinity of the sea water is according to chemical analysis 1 ) of 

 sample secured in the spring of 1904, 1.649 per cent. The surface 

 temperature of the water at noon was +12°C. with an atmospheric 

 temperature of +16°C. (Ill, 10, 04.) 



Pine forest on sand field in lee of the dune chain at Point Pinos, Pacific Grove, 

 Oal. The advancing dune can be seen in background. 



PHOTOGRAPH BY THE AUTHOR. 



Between Pescadero and Santa Cruz on the San Francisco Peninsula 

 sandy shores and small dune accumulations occur in various places. 

 During the summer 1904 a visit was made to this district. The char- 

 acter of the dune sand corresponds to that of the San Francisco 

 district. 



1) Made by Mr. R. W. Dodd in the chemical laboratory of Stanford Uni- 

 versity through courtesy of Dr. J. M. Stillman. 



