@Override
 public Object getValueAt(int row, int col) {
   if (col == 0) return row + 1;
   else
     return MeasuresTableModel.format_number(
         GearScheme.get_path(row).shaft_speed(GearScheme.get_shaft(col - 1)));
 }
 @Override
 public String getColumnName(int i) {
   if (i == 0) return "path";
   else return GearScheme.get_shaft(i - 1).toString();
 }