466 
same electroscope was used, but two shaking cans were used, the larger 
of which had three stop cocks so that two volumes of water could be had. 
TABLE 4. 
C.J.S. Spring. August 5, 1914. Temperature of water 12.5° C. Temperature of air 30° C. 
ile 10 108k 
Minve OLD eeANNING eecreee eames eee Osi ae by s-y- here R46 fas. sane 2.00 p. m. 
Volume of watern: cock: he see cas eee BOW CCTS tps SL OOMGER See 5.00 liter. 
Voltinxe Of/ ait och nate cre sacs ones act SOAK evade nile ors AEM Oe ke crcinoebsoraete 2.10. 
@uries 21022iper liter... 4. eae oe ADD EXGLO=1Se cies ss ASH X10-125 ah. oe 443 X10-!2. 
These observations were taken every minute and the mean deflection 
from 15 minutes to 20 minutes from the time of putting the emanation in the 
ionization chamber, was used. By referring to an experimental curve (Fig. 
8), the maximum deflection per minute or the deflection at the end of three 
hours was calculated. A better agreement could have been obtained if the 
interval from the end of one experiment to the beginning of the next had been 
three hours or more. 
Fig. 8 is a curve showing actual observations during a period of three 
hours taken with a sample of water from Hottle Spring. The observations 
have been reduced to a scale of 100% for the maximum. The curve marked 
“Decay A and C”’ is made by observing the deflections after the emanation 
has been pumped out. By means of this experimental curve observations at 
any time can be reduced to the maximum or three-hour values. For exact 
work the emanation should be placed in the electroscope and allowed to stand 
for three hours and several observations made and the mean used. The 
curve is for all practical purposes horizontal from three to four hours. 
In all these observations the deflections have been corrected for the 
natural leak of the electroscope due to the natural ionization of the air. 
Before giving results, I shall speak of some factors which may influ- 
ence the results. Since the emanation gas is dissolved in the water and is 
removed by boiling or by shaking, care should be used in filling the shaking 
‘an. Immerse the can in a pool as close as possible to the source and allow 
the water to flow in gently. Filling by dipping and pouring with a smaller 
vessel removes some of the gas. If before the water issues from the ground 
it trickles over rocks in the presence of air which is not charged with emana- 
