This investigation includes measurements on waters from Lake Arrowhead, Arrowhead Hot Springs, Harlem Hot Spgs., Pacific Ocean, and from numerous wells and tunnels of the Pasadena and neighboring water supplies. It also includes measurements on rocks, soils, and crude oil.
The activity of the water of Lake Arrowhead is found to be about one hundred times smaller than the minimum that could be detected in the electroscopes used for cosmic ray measurements. This lake is, therefore, very suitable for the cosmic ray measurements.
The Pasadena wells yield waters approximately one thousand times as active as the Lake Arrowhead water; and is, therefore, not suitable for cosmic ray measurements.
The ratio between the activity of the soil at Lake Arrowhead and that of the soil on the campus, as obtained by Millikan and Cameron, from their cosmic ray data, is in good agreement with the results in this report.
The average radium content of the acid intrusive rocks in the vicinity of Devil's Gate Dam, according to the measurements so far made, is 2.3x10-12 gms. of radium per gm. of rock.
The emanation in crude oil was found to be of the same order of magnitude as that found in well water.
Pasadena tap water contains about 1 eman, or 1x10-10 curies per liter, while the average of the sources is about five times as great.
