Vernier measuring device

Claim 1

A MEASURING DEVICE, COMPRISING: FIRST AND SECOND ELONGATED HOLLOW CYLINDERS, WITH SAID SECOND CYLINDER PARTIALLY TELESCOPICALLY RECEIVED WITHIN SAID FIRST CYLINDER, SAID FIRST CYLINDER HAVING AN END CLOSURE CLOSING ONE END THEREOF, WITH THE SECOND END BEING OPEN TO TELESCOPICALLY RECEIVE SAID SECOND CYLINDER, SAID SECOND CYLINDER HAVING THE FIRST AND SECOND ENDS THEREOF CLOSED WITH AN END CLOSURE, A STEM NON-ROTATATIVELY FIXED TO SAID FIRST CYLINDER END CLOSURE AND EXTENDING AXIALLY THEREOF INTO SAID SECOND CYLINDER, SAID SECOND CYLINDER HAIVNG AN APERTURE IN THE END CLOSURE AT A FIRST END THEREOF RECEIVING SAID STEM, A RELATIVELY ELONGTED SLIDE NON-ROTATIVELY FIXED TO SAID STEM AND MOVABLY MOUNTED WITHIN SAID SECOND CYLINDER, A SPRING EXTENDING BETWEEN SAID SLIDE AND ONE OF THE SECOND CYLINDER END CLOSURES URGING SAID SLIDE TOWARD THE OTHER SECOND CYLINDER END CLOSURE, GUIDE MEANS RIGIDLY CONNECTING SAID SECOND CYLINDER END CLOSURES INTERIORLY OF SAID CYLINDER, SAID SLIDE BEING NON-ROTATIVELY, SLIDABLY MOUNTED ON SAID GUIDE MEANS WHEREBY SAID CYLINDERS ARE MAINTAINED AGAINST RELATIVE ROTATIONAL MOVEMENT AND WHEREBY A CONSTANT BEARING SURFACE IS PROVIDED BETWEEN SAID SLIDE AND GUIDE MEANS IRRESPECTIVE OF THE DEGREE OF TELESCOPING OF SAID CYLINDERS, LATERALLY-EXTENDING GLIDES SECURED TO THE OUTSIDES OF SAID CYLINDERS AT SAID FIRST CYLINDER SECOND END AND SAID SECOND CYLINDER SECOND END FOR CONJOINT ACTION IN MEASURING, SAID FIRST CYLINDER BEING EQUIPPED WITH A LONGITUDINALLYEXTENDING SLOT FOR REVEALING A PORTION OF SAID SECOND CYLINDER, SAID CYLINDERS ADJACENT SAID SLOT AND ON SAID PORTION BEING EQUIPPED WITH TRUE AND VERNIER SCALES, AND SET SCREW MEANS ON SAID FIRST CYLINDER FOR MAINTAINING SAID SECOND CYLINDER IN FIXED RELATION THERETO.