Acoustic well logging system

Claim 1

IN AN ACOUSTIC WELL LOGGING SYSTEM HAVING CABLESUPPORTING MEANS FOR MOVEMENT ALONG THE BORE OF A WELL, THE COMBINATION COMPRISING A PAIR OF SOUND CHAMBERS, EACH FORMED BY AN ELONGATED RIGID METALLIC CYLINDER OF HIGH ACOUSTICAL CONDUCTIVITY WITH WALLS PRESENTING A LARGE CONTACT AREA FOR BORE HOLE FLUIDS AND OF ADEQUATE THICKNESS TO WITHSTAND THE HYDROSTATIC PRESSURES EXISTING IN DEEP BORE HOLES, A METALLIC STRUCTURE OF LOW ACOUSTICAL CONDUCTIVITY INTERPOSED BETWEEN AND INTERCONNECTING ADJACENT ENDS OF SAID CHAMBERS AND FORMING A HIGH ACOUSTIC IMPEDANCE BETWEEN THEM, AN ACOUSTICALLY CONDUCTIVE LIQUID AT LEAST PARTIALLY FILING EACH OF SAID CHAMBERS, A TRANSDUCER FOR EACH OF SAID CHAMBERS, AND MEANS SUPPORTING EACH OF SAID TRANSDUCERS IN SPACED RELATION WITH THE WALLS OF ITS ASSOCIATED SOUND CHAMBER FOR TRANSMISSION AND RECEPTION RESPECTIVELY OF ACOUSTICAL ENERGY TO AND FROM SAID WALLS SUBSTANTIALLY ENTIRELY BY WAY OF SAID LIQUID.