A balancing vertical load device for a motor, to be used in conjunction with a vertical driving device with a force- and position-controlled motor, comprising a motor assembly and a sealed air pressure system. Also, a process for treating dry soil to reduce dust generation due to movement of traffic or air thereover. The retainer is slidable in and along the sleeve. The varistors are variable resistor elements having a current tolerating ability greater than that of the first overvoltage protection elements.