acts_as_ferret: using an index outside of the application

Hello,

Does anyone who has worked with acts_as_ferret know how to point the search to an index outside of the application?

I've tried changing the environment.rb: module FerretConfig   include Ferret

  INDEX = Index::Index.new(:path => '/my_other_applications_index/ index/')

end

"Asked for a remote server ? true, ENV["FERRET_USE_LOCAL_INDEX"] is nil, looks like we are not the server Will use local index."

Many Thanks