Boundary mark for marking of boundary points of grounds

Claim 1

A READILY VISIBLE DEVICE FOR MARKING THE BOUNDARIES OF LAND, SAID DEVICE BEING ENGAGEABLE BY A TORQUE APPLYING TOOL, COMPRISING: AN ELONGATED CYLINDRICAL AND METALLIC TUBE OF SUBSTANTIALLY UNIFORM DIAMETER HAVING UPPER AND LOWER ENDS; A CONE-SHAPED POINT RIGIDLY SECURED TO THE LOWER END OF SAID TUBE AND CONVERGING DOWNWARDLY AND COAXIALLY THEREFROM; A HELICAL BORING THREAD FIXED ON SAID POINT, SAID THREAD BEING ADAPTED TO MOVE SAID POINT INTO THE GROUND IN RESPONSE TO ROTATION OF SAID TUBE; A SUBSTANTIALLY POLYGONAL AND PLASTIC HEAD RIGIDLY SECURED ON AND AROUND THE UPPER END OF SAID TUBE AND EXTENDING RADIALLY OF SAID TUBE BEYOND THE SIDE WALLS THEREOF FOR ENGAGEMENT BY THE TORQUE APPLYING TOOL, WHEREBY SAID TUBE CAN BE ROTATED AROUND ITS LENGTHWISE AXIS, SAID HEAD HAVING AN EASILY VISIBLE AND DETECTABLE APPERANCE, SAID HEAD HAVING A SUBSTANTIALLY FLAT AND IMPERFORATE UPPER SURFACE; AND A WEATHER RESISTANT, PLASTIC COVERING EMBRACING SAID TUBE FROM SAID HEAD TO SAID POINT.