EFFECT OF TROPICAL SUNLIGHT ON THE ATMOSPHERE. 279 



Very slight activity. 



23. Black sand from Ambos Camarines from claims of Ingersoll. 



Time. 



(a. m. ) 



9.45 

 10.15 



Slight activity. 



24. Black sand from Lamao Beach, Manila Bay, Bataan Province. 





Volts 



Volts. 



per hour 



167.1) 

 167.11 



9.0 



Time, 

 (p.m.) 



12.50 



3.20 



Volts. 

 152.6( 

 152.fi I 



Volts 

 per hour. 



5.3 



Very slight activity. 



Nonmagnetic portion of the same. 



Time, 

 (p. m.) 

 12.00 

 12.45 

 Slight activity. 



25. Black sand collected in Paracale, Ambos Camarines. 



Volts. 



Volts 

 per hour 



195.7) 

 189.7] 



7.5 



Time. 



(a. m.) Volts. 



9.40 179.0 



10.10 176.1 



Very slight activity. 



Nonmagnetic portion of the same. 



Time, 

 (a. m.) 



8.30 



9.30 



Slight activity. 



26. Black sand from Calabasa River, Nneva Ecija. 



Volts 

 per hour. 



5.8 





Volts 



Volts. 



per hour 



139.5) 





131.31 



8.9 



Time, 

 (a. m.) 



8.00 



8.40 



Volts. 



212.61 



207.5) 



Volts 

 per hour. 



6.8 



Volts. 



Volts 

 per hour 



216.01 

 192.8) 



7.1 



Slight activity. 



27. Black sand from O'Connell River, Tarlac Province. 



Time, 

 (a. m. ) 



9.45 

 11.00 

 Slightly active. 



28. Beach sand from Lamao, Manila Bay, Bataan Province, at places where it 

 is not black. 



Time, 

 (a. m. ) 



8.45 

 10.05 



Volts. 



Volts 

 per hour 



190.8) 

 182.9) 



5.3 



