1. A POLE UNIT FOR A HIGH-VOLTAGE CIRCUIT BREAKER COMPRISING: (A) A PAIR OF CIRCUIT INTERRUPTING DEVICES EACH INCLUDING COOPERATING SEPARABLE CONTACT MEANS FORMING A GAP THEREBETWEEN UPON SEPARATION THEREOF; (B) MEANS FOR SERIALLY CONNECTING SAID PAIR OF INTERRUPTING DEVICES INTO A PHASE OF AN ELECTRIC HIGH-VOLTAGE CIRCUIT; (C) MEANS SHUNTING ACROSS EACH OF SAID PAIR OF INTERRUPTING DEVICES INTO A PHASE OF AN ELECTRIC HIGH-VOLTAGE CIRCUIT; (C) MEANS SHUNTED ACROSS EACH OF SAID PAIR OF INTERSTRUCTUALLY DIFFERENT FROM THE OTHER; AND (E) ONE OF SAID PAIR OF INTERRUPTING DEVICES BEING ADAPTED TO FORM A GAP UPON SEPARATION OF SAID SEPARABLE CONTACT MEANS HAVING A RELATIVELY RAPID INITIAL RATE OF DIELECTRIC RECOVERY AND A RELATIVELY SMALL ULTIMATE DIELECTRIC STRENGTH; AND (F) THE OTHER OF SAID PAIR OF INTERRUPTED DEVICES BEING ADAPTED TO FORM A GAP UPON SEPARATION OF SAID SEPARABLE CONTACT MEANS HAVING A RELATIVELY SLOW INITIAL RATE OF DIELECTRIC RECOVERY AND A RELATIVELY HIGH ULTIMATE DIELECTRIC STRENGTH.