Currents; the former is polarized and responds to reversals of current, while the latter is non-polarized and responds only to the increased current from K2 irrespective of the direction of that current.
All nature responds in rich and rapid growth to the garish light and intense heat of the long, splendid days.
The supervisory lamp associated with the peg in the wanted subscriber's jack glows from the time that the peg is inserted until the subscriber responds, when it darkens, in which condition it remains until the subscriber restores the receiver to the hook and causes the lamp to light up again.
The four telephones on a circuit are so wired that the relays 9-- P ..,, connect two of the bells between each wire and fl-- 0 7-..9 *"y earth, and further that one of each pair of bells responds to positive and the other to negative o-- pulsations.
Of the four bells connected to a circuit each responds to a different frequency.