Thus  far  Congress  has  not  assumed  to  fix,  in  any  authori-
tative manner,  the  standard  of  weights  and  measures  ;  the
legislation  of  the  states  has  not  been  interfered  with.  Even
under  the  pressure  brought  to  bear  by  the  advocates  of  the
decimal  system,  the  utmost  that  has  been  done  is  the  passage
of  a  permissive  statute.  Should  the  national  legislature,  how-
ever, change  its  policy,  and  fix  a  standard  for  the  whole
country,  all  inconsistent  state  legislation  would  be  a  nullity.
SECTION   VII.
THE   POWER   OVEK   THE   POSTAL   SERVICE.
