Pillar of the White Hand

After  his   renunciation   of   the  White Council in TA 2953, Saruman  adopted  the  heraldic  emblem  of  a  white hand  on  a  field  of  black. His armies   carried   banners   bearing   the  symbol, which was also emblazoned on  their  shields  and  helmets. The most  prominent   and   permanent   display  of  this  device  took  the  form  of  a  great  pillar  of  black  stone  carved  in  the  likeness  of  a  hand  and  painted  white. Its finger  angled  northward,  toward  the  gates  of  Isengard,  some  five leagues beyond. Some    had     speculated     that  Saruman   had   a   subtle   connection  with the pillar, enabling him to sense  the  presence  of  any  who  passed  within  some  distance—ten  miles,  many  guessed—of   the   structure,   thereby  alerting   him   to   unwanted   visitors  in  his  land. This belief  was  true  in  a  certain  respect. Whenever any  being  of  power  came  within  four  leagues  of  the  Pillar  of  the  White  Hand,  Saruman was able  to  detect  the  being’s  presence. In essence,   the   Pillar   acted  as   the  emanation   point   of   a   powerful  form   of  a Sense  of Power    spell,  with  a  range  of  four  leagues.