1. A CIRCUIT BREAKER HAVING A HOUSING INCLUDING AN ARCING CHAMBER HAVING SEPARABLE CONTACTS THEREIN SURROUNDED BY A FLUID INSULANT, MEANS FOR INCREASING ITS STATIC PRESSURE WITHOUT CONVERSION INTO KINETIC ENERGY BEFORE SAID CONTACTS SEPARATE, SAID MEANS BEING POSITIONED IN SAID HOUSING REMOTELY FROM SAID ARCING CHAMBER, AND OVERFLOW CHAMBER, A VALVE CONNECTING SAID OVERFLOW CHAMBER IWTH SAID ARCING CHAMBER, SAID VALVE CLOSING IN RESPONSE TO A FIRST FLUID PRESSURE IN SAID ARCING CHAMBER, AND A SAFETY VALVE IN SAID ARCING CHAMBER OPENING IN RESPONSE TO A SECOND FLUID PRESSURE, SAID SECOND FLUID PRESSURE BEING HIGHER THAN SAID FIRST FLUID PRESSURE.