Mise a la masse data acquired during a tracer test at Gay Stamp Sands.
The local current electrode is in the injection well. The distant current
electrode is about 100 meters away in one direction and the reference
voltage electrode is about 100 meters away in the other direction.
The injection well is about 1 meter deep. About 60 liters of water and
 1 kg of salt was  poured into the injection well. The original v/i data
are presented in in the left hand column of figures. The data in the
right hand column are ratios of the data at t=20 min divided by data at t=0.