Meridian and latitude indicator

Claim 1

A DIRECTION-INDICATING GYROSCOPIC INSTRUMENT COMPRISING: A SUPPORT; A ROTARY FRAME ON SAID SUPPORT, ROTATABLY MOUNTED ABOUT A VERTICAL AXIS, AND HAVING PASSAGE MEANS FOR CONDUCTING PRESSURIZED GAS TO ONE OF ITS SURFACES AND A DIRECTION-INDICATING DATUM MEANS; MEANS FOR MAINTAINING THE ROTARY AXIS OF SAID FRAME IN A VERTICAL POSITION AND PREVENTING JOSTLING OF THE FRAME WHEN SAID SUPORT IS SHAKEN COMPRISING A PAIR OF ORTHOGONALLY ARRANGED HORIZONTAL-AXIS BEARINGS, PROVIDING FOR PIVOTING OF THE FRAME ON SAID SUPPORT ABOUT PERPENDICULAR AXES, A MOTOR AT EACH OF SAID BEARINGS, GEARING DRIVABLY CONNECTING SAID MOTOR TO THE FRAME FOR TURNING IT ON ONE OF SAID BEARINGS, AND LEVEL-SENSITIVE MEANS FOR CONTROLLING SAID MOTORS; A CUPSHAPED ROTARY ELEMENT, HAVING AN UPPER CONCAVE SURFACE, MOUNTED ON SAID FRAME FOR ROTATION ABOUT SAID VERTICAL AXIS, HAVING A PLURALITY OF BALANCEDLY SPACED HOLES DEBOUCHING ON SAID CONCAVE SURFACES AND MEANS FOR CONDUCTING PRESSURIZED GAS FROM SAID PASSAGE MEANS TO SAID HOLES, WHEREBY A GASEOUS BEARING FILM IS PROVIDED ON THE CONCAVE SURFACE; A MOTOR BALANCEDLY MOUNTED ON SAID FRAME BELOW SAID CONCAVE SURFACE; POWER-TRANSMISSION MEANS BETWEEN SAID MOTOR AND ROTARY ELEMENT; A SINGLE, BALANCED, SUBSTANTIALLY SPHERICAL, GYROSCOPIC ROTOR FREELY MOUNTED ON SAID GASEOUS FILM AND CONCAVE SURFACE, ROTATED BY SAID FILM AT THE SPEED OF SAID MOTOR AFTER IT HAS RUN A WHILE, HAVING AN AXIS THAT CONTINUALLY LAGS RELATIVELY TO SAID VERTICAL AXIS AND FORMS AN ANGLE WITH THIS AXIS IN THE EAST-WEST VERTICAL PLANE THAT CHANGES WITH CHARGING LATITUDE AND IN ALL LOCTIONS OTHER THAN ONE OF THE EARTH''S POLES IS PROPORTIONAL TO THE LATITUDE OF THE INSTRUMENT; RADIANT ENERGY REFLECTING MEANS ON SAID ROTOR; MEANS ON SAID FRAME FOR DIRECTING A BEAM OF RADIANT ENERGY TO SAID REFLECTING MEANS AND RECEIVING FROM IT REFLECTED ENERGY; MOTIVE MEANS, CONTROLLED BY SAID REFLECTED ENERGY, CONNECTED TO SAID SUPPORT AND TO SAID FRAME, FOR ROTATING THE FRAME ABOUT SAID VERTICAL AXIS AND THUS RETURNING SAID DATUM MEANS TO ITS DIRECTION-INDICATING POSITION WHEN SAID SUPPORT AND FRAME HAVE BEEN ROTATED RELATIVELY TO THE EAST-WEST VERTICAL PLANE.