Polarimeter

Claim 1

IN COMBINATION: MEANS FOR PROJECTING A BEAM OF PLANE-POLARIZED LIGHT ALONG A PREDETERMINED OPTICAL PATH; FARADAY CELL MEANS HAVING FARADAY CORE MEANS LOCATED ON SAID PATH FOR ROTATING THE PLANE OF POLARIZATION OF SAID BEAM OF LIGHT, SAID FARADAY CELL MEANS HAVING FARADAY COIL MEANS FOR PRODUCING A MAGNETIC FIELD IN SAID FARADAY CORE MEANS ALONG SAID OPTICAL PATH; A SOURCE OF DIRECT CURRENT CONNECTED TO SAID FARADAY COIL MEANS; AN ANALYZER MOUNTED TO RECEIVE SAID BEAM OF LIGHT, SAID ANALYZER BEING MOUNTED WITH ITS PLANE OF POLARIZATION CROSSED RELATIVE TO THE AVERAGE POSITION OF THE PLANE OF POLARIZATION OF SAID BEAM OF LIGHT AT SAID ANALYZER; A PHOTODETECTOR ARRANGED TO RECEIVE LIGHT TRANSMITTED BY SAID ANALYZER OF PRODUCING AN ELECTRICAL SIGNAL THAT VARIES IN MAGNITUDE IN ACCORDANCE WITH THE VARIATION OF INTENSITY OF THE PLANE-POLARIZED LIGHT TRANSMITTED THROUGH SAID ANALYZER; AN AMPLIFIER, SELECTIVELY RESPONSIVE TO A FREQUENCY COMPONENT OF SAID SIGNAL OF A PREDETERMINED FUNDAMENTAL FREQUENCY, FOR AMPLIFYING ALTERNATING CURRENT COMPONENTS OF SAID SIGNAL DEVELOPED IN RESPONSE TO