[ruby-talk:03087] Exceptions documented where?

Doing the following:

------- snip -------
require 'net/http'
# ...
begin
  host = Net::HTTP.new( 'mdas10.urz.uni-magdeburg.de', 4575)
rescue
  puts "Exception of type " + $!.type + " caught."
end
------- snap -------

while the server is down results in

------- snip -------
/usr/local/lib/ruby/1.4/net/protocol.rb:406:in `new': Connection refused - connect(2) (Errno::ECONNREFUSED)
        from /usr/local/lib/ruby/1.4/net/protocol.rb:406:in `initialize'
        from /usr/local/lib/ruby/1.4/net/protocol.rb:205:in `new'
        from /usr/local/lib/ruby/1.4/net/protocol.rb:205:in `connect'
        from /usr/local/lib/ruby/1.4/net/protocol.rb:165:in `start'
        from /usr/local/lib/ruby/1.4/net/http.rb:229:in `connecting'
        from /usr/local/lib/ruby/1.4/net/http.rb:142:in `get'
        from ./bib.rb:21
------- snap -------

Why is http.rb not throwing an exception here? In case it would -
where would that be documented? In case I am not completely mistaken,
/usr/local/lib/ruby/1.4/net/http.rb does not mention any exceptions.

Any pointers are much appreciated.

        Roland