But  it  cannot  be  that  a  vessel  actually  captured  in  attempting
to  enter  a  blockaded  port,  after  warning  entered  on  her  log  by
a  cruiser  off  that  port  only  a  few  days  before,  could  dispute  the
efficiency  of  the  force  to  which  she  was  subjected.
As  we  hold  that  an  effective  blockade  is  a  blockade  so  effec-
tive as  to  make  it  dangerous  in  fact  for  vessels  to  attempt  to
enter  the  blockaded  port,  it  follows  that  the  question  of  effec-
tiveness is  not  controlled  by  the  number  of  the  blockading  force.
In  other  words,  the  position  cannot  be  maintained  that  one
modern  cruiser  though  sufficient  in  fact  is  not  sufficient  as  matter
of  law.
Even  as  long  ago  as  1809,  in  The  Nancy,  1  Acton,  63,  where
the  station  of  the  vessel  was  sometimes  off  the  port  of  Trinity
and,  at  others,  off  another  port  more  than  seven  miles  distant,
it  was  ruled  that :  "  Under  particular  circumstances  a  single  ves-
sel may  be  adequate  to  maintain  the  blockade  of  one  port  and
co-operate  with  other  vessels  at  the  same  time  in  the  blockade
of  another  neighbouring  port";  although  there  Sir  William
Grant  relied  on  the  opinion  of  the  commander  on  that  station
that  the  force  was  completely  adequate  to  the  service  required
to  be  performed.
The  ruHng  of  Dr.  Lushington  in  The  Frandska,  above  cited,
was  to  that  effect,  and  the  text-books  refer  to  other  instances.
