An eccentric, jolly old ferret keeper (Ed Lipinski who runs Ferrets
Northwest) once showed me how to install a ferret in a harness properly
to prevent both escape and damage to the ferret.  Use a kitten-size
leather or nylon figure-8 harness, extend both front paws, and actually
pick the ferret up by the loose end of the harness and gently bounce it
tight.  The harness will seem pretty tight, but make sure that you can
fit a small finger in under the harness.  If necessary (it will be the
first time), note the required spot for a hole and drill it using a hot
wire (coat hanger works for me) for nylon or an awl for leather.  On all
the harnesses I've found, I also have to trim off a couple of inches of
excess harness since kitten-size harnesses are too big, even allowing for
future ferret growth.
 
Check the size every time you harness up your ferret, since they can
lose or gain weight that would allow them to escape or injure them.
Add holes as necessary, at least 3/8 or 1/2 inch apart to keep the
harness strong.
 
Our guys all thought they were being tortured to death the first time
we put a harness on them, but they quickly learned to look forward to
a walk (oh joy!) when the harness went on.  Before they learned, they
scooted around on their chests for 15 minutes or so, trying to scrub
the damnable things off.
 
Ed uses this technique on many ferrets, as he regularly stakes out 6 or
more at a time to allow them to dig and enjoy the (feeble, infrequent
Pacific Northwest) sunshine.  The one time one of Ed's many ferrets got
loose, my girlfriend spotted a big, friendly, whole male happily digging
about a meter from where he was normally leashed so I walked over and
picked him up.  It turns out that the buckle had rusted, weakened, and
failed.  But other than that, this technique has been totally reliable.
 
I don't know that I'd let my ferret go on a 50 foot rope, but maybe a 6
foot nylon lead would be OK while reading.  While walking and actively
supervising the ferret, I normally use one of those nylon webbing
retracto-leashes.  I forget the brand name, it might be something like
Flexi-leash or Vari-leash, but they come in several sizes, for
Chihuahuas to Mastiffs.  (I get the Chihuahua size, of course, and it
extends maybe )
 
Oh, another disadvantage to a 50 foot rope is that red-tailed hawks
are purportedly interested in and capable of preying on ferrets.  Ed
has that risk reduced by keeping a resident tame crow that sounds the
alarm when it sights any predatory birds.  You'd be amazed at the way
the crow's call gets the ferrets' attention, and of course, Ed's.
Anyway, if you're busy reading, a shorter lead, firmly attached to the
ground, might keep your ferret within your quick and easy reach in
the event of a hawk encounter.
 
Happy Ferret-Keeping!
Dennis
P.S.  Your ferret *does* have a collar with a bell, right?  If not,
you should definitely get one.  I wouldn't take any of my guys outside
without one, and I think they keep ferrets safer indoors too.  I'm
pretty sure the Ferret FAQ describes one made with heavy-duty toilet
ball chain.  Sizing of collars is quite a bit looser than with
harnesses--see the FAQ...
[Posted in FML issue 1226]