182 WILLIAM S. COOPER 



by grassland, chaparral, and open oak forest (Quercus agrifolia 

 Nee and Q. lohata Nee). The altitudes are negUgible. The 

 eastern foothill region (Sta. 5-7), several kilometers wide west 

 of Palo Alto, narrows almost to extinction southeastward, the 

 mountains fronting abruptly upon the valley. The altitudes 

 of stations occupied range from 120 m. to 250 m. The vegeta- 

 tion consists dominantly of chaparral of several types, with oak 

 forest {Quercus agrifolia most important) in ravines and on steep 

 north slopes. Close to the main mountain front a few redwoods 

 occur beside streams. The western foothills are indefinite in 

 extent, merging gradually with the higher mountains to the 

 east. The stations occupied, both of which are in valleys, were 

 97 m. and 106 m. in altitude. The hills are mainly grassy, 

 with little chaparral and few oaks. Tongues of redwood extend 

 down the cafions toward the ocean. The coast in part is bordered 

 by a flat strip 2 km. wide or less; in other places the hills come 

 to the ocean, and steep slopes and sea cliffs occur. The coast 

 station at Tunitas was at the top of one of these cliffs, 70 m. 

 above tide. The vegetation of the seaward facing slopes is the 

 characteristic coastal scrub, including Baccharis pilularis DC, 

 Rhamnus calif ornica Esch., Rhus diver siloba T. & G., and Lupinus 

 orhoreus Sims. 



While interested in the problem of the redwood, my attention 

 was called by Dr. Forrest Shreve to a simple means for measuring 

 total precipitation for long periods, which is in use among the 

 ranchers in the vicinity of Tucson, Arizona, and which was used 

 by Dr. Shreve in his studies in the Santa Catalina Mountains. 

 This device seems to have sufficient possibilities for usefulness 

 to merit a full description. I wish also to suggest some modi- 

 fications which seem to me to be improvements. The instru- 

 ment consists essentially of a container of convenient size fitted 

 with a tin funnel to receive the rain. A little kerosene, put into 

 the container, floats upon the surface of the water and prevents 

 loss by evaporation. The precipitation is determined by pour- 

 ing the contents into a graduate. The amount of the kerosene 

 is deducted and the volume of water is divided by the receiving 

 area of the funnel. 



