1. AN AUGER ASSEMBLY COMPRISING IN COMBINATION WITH A DRIVE BAR, A SUBSTANTIALLY CYLINDRICAL ENCLOSURE SECURABLE TO AND ROTATABLE BY SAID DRIVE BAR, A CENTRALLY LOCATED CENTERING COMPONENT BELOW SAID ENCLOSURE, SAID DRIVE BAR EXTENDING THROUGH SAID ENCLOSURE AND BEING JOURNALLED FOR ROTATION IN SAID CENTERING COMPONENT, AT LEAST ONE CUTTER CHANNEL FORMED THROUGH SAID ENCLOSURE AND EXTENDING FROM ADJACENT SAID DRIVE BAR, RADIALLY TO THE PERIMETER OF SAID ENCLOSURE, A TRAVELLING CUTTER ASSEMBLY MOUNTED FOR RADIAL MOVEMENT ALONG SAID CUTTER CHANNEL, AND MEANS OPERATIVELY CONNECTING SAID CUTTER ASSEMBLY TO SAID DRIVE BAR TO MOVE SADI CUTTER ASSEMBLY OUTWARDLY FROM ADJACENT SAID DRIVE BAR TO SAID MEMBER OF SAID ENCLOSURE AS SAID DRIVE BAR IS ROTATED, SAID MEANS TO MOVE SAID CUTTER OUTWARDLY INCLUDING A RACK BAR MOUNTING SAID CUTTER ASSEMBLY, GEAR MEANS OPERATIVELY CONNECTING SAID RACK BAR TO SAID DRIVE BAR, AND MEANS MOUNTED IN SAID ENCLOSURE ADAPTED TO DISENGAGE SAID RACK BAR FROM SAID GEAR MEANS WHEN SAID CUTTER ASSEMBLY REACHES THE PERIMETER OF SAID ENCLOSURE.