How did it become the fashion for stylish gentlemen to carry canes as an
accessory, and what did they ever actually do with them (aside from,
say, twirling their top hats on them while dancing)?  Obviously I am
not referring to contemporary fashion but to Edwardian or perhaps
Victorian style.

Pure curiosity, this one.  As a person who occasionally has knee
trouble and uses a conventional cane as an aid to walking, I find it a
nuisance to have only one hand free and wonder what fashion benefit
might be worth that disadvantage.

Thank you,
Archae0pteryx

19th century dress canes often came with a hidden advantage: a small
sword that could be withdrawn and used for self-defense. I doubt that
this is the sole explanation, but it might be one reason why gentlemen
carried canes. The ability not only to club a ruffian with the cane,
but also to stab the miscreant with a blade would come in handy if one
were attacked on the street.

Hi, Pink,

Hmm, yes, that sounds right.  I seem to recall that some contained a
little nip of something refreshing, too.  But these amenities seem to
have been afterthoughts and probably not the reason that canes came
into fashionable use in the first place.

What I am wondering is if men just *carried* them or if they *did*
something with them, such as flourish them expressively during
conversation, poke at odd bits of something in the shrubbery, clear
debris from their path, wave them to hail a hansom, knock ashes off
one another's cigarettes, signal their courtship intentions and
qualifications to women, thump them to indicate impatience or
displeasure, and so on (many possibilities come to mind).  Of all the
hypothetical uses, though, was any enough to bring them into fashion,
or why did people start carrying them in the first place?  Were they
indeed actual or symbolic weapons?  Was it just to ape some monarch or
monarch-to-be-who actually used a cane prosthetically?  Or did some
canemaker hit the jackpot with a really gung-ho marketing consultant?

Tryx

And that from You on a peaceful Sunday with shocking overtones about
social classes distinctions! :-)  You read too much A.C. Doyle!
But you may be right in a way.  I think carrying a walking stick came
in about the time swords went out of style for everyday dress; Louis
?teenth, 17th century, then longer, breast-high sticks.  No gentleman
would be about without one.  (We'll leave the last half of Pinky's
name out of this discussion.)
And maybe  - like the overly long sleeves of upper class Chinese in
past centuries -  carrying a stick signified that one didn't need
one's hands free for any kind of manual work.  (This is just my
cross-cultural suggestion.)

With time, the sticks became shorter  - the long ones being
inconvenient in carriages or without a servant to hand them to. 
Eventually, they were so short that it was handy to have a horizontal
grip, which is, of course, more helpful if one needs one for support
(war veterans, gout sufferers, etc.).
Formal dress  - tails and tophat -  are carry-overs of earlier styles
of dress, as fashion plates show, and the stick belong to the
ensemble.

Interestingly, every seat in the 1908 church here (Germany) has a
little rubber-padded clip for the gentleman's hat and a hook for his
cane or umbrella.
               -    -    -
I composed that before or while Tryx (Hi!) posted her comment, but GA
wouldn't let me post it then.

Yes indeed, a nip of something, a watch, compass, snuff box, all are
to be found, and, even today, an umbrella within a telescoping case. 
(Great traditional cane and brolly store south of Bloomsbury Sq.)

I am sure Tryx is right, if one doesn't have a game leg, it is just
natural to play with a stick or cane, and the earlier one's I
mentioned were made for strutting  - well, better, ideal for strutting
-  like a British drum major, placing it out ahead and flourishing out
to the side as he steps closer. It just comes naturally.  And the drum
major's stick is definitely a last vestige of this style. (Well,
"Black Stick"'s when the Queen speaks in Parliament is too.)

And with your mentioning it, Tryx, I can well imagine that there
developed a code of gestures similar to that for ladies' fans ..., and
not just thump them in impatience or displeasure  - what easier and
natural indication that one wished to end a conversation than to grasp
one's stick and place it to stand up?

Borrow one and play with it, or a man's umbrella.  Even the 70 y/o
chaplain at my school used to let his cane circle.  I'll use my
gramp's (1850-1945) if I ever need it.

Hello archae0pteryx-ga~

Your question is interesting, but not really answerable. No one can
tell you with 100% certainty why canes came into vogue. Therefore, I'm
not posting this as an answer. However, as a historic fashion expert,
I can give you some thoughts:

Swords and flasks in canes weren't all that common. Some did exist,
but the majority of canes were just that: canes. Canes as a fashion
accessory really came into vogue in the 18th century, and there may be
several reasons for them:

* Men often carried swords previous to the 18th century. Slowly,
constant sword carrying became associated with military men only.
Still, perhaps men were accustomed to carrying something.

* Canes were a sign of wealth and status. Poor folks didn't carry
them, and neither did most of the middle class (in the 18th century).
As swords became associated with the military, a true gentleman did
not want to associate with them on a day-to-day basis.

Canes were primarily decorative, much like the tight pants and absurd
hats of the 18th century. They were expensive trinkets designed to
show of status, not necessarily meant to be useful.

I hope this helps! :)

Kriswrite

I carry a cane (lower back injury), and frequently hit people and/or
animals with it when they get in my way.  Perhaps that's why they were
popular in the 18th century, a time when it may have been more
acceptable to whack things with a stick.

Recently I heard something interesting in a Jack the Ripper film
called "The Ripper," starring Patrick Bergin. At one point a Scotland
Yard Inspector remarks that a certain walking-stick is "a club cane."
He goes on to say that all members of an upscale gentlemen's club
carry a cane of identical design.

Perhaps the carrying of a cane as part of formal garb is a bit like Mensa's map pin.

Yes, it is very convenient to have a solid stick in your hand when you
are somewhere where there may be riffraff about.  And canes  - even
without hidden swords -  were a potential means of selfdefense. 
Sherlock Holmes was an expert at "single stick", a form of fencing
with cane (The Speckled Band).

I wanted to verify my 17th c. date with a Dutch painting, but
G-Pictures and I didn't mesh on finding one, but Kriswrite-ga will
certainly know the style, loose kneepants with flounces around the
knees.  Typical pictures with such are church and other interiors,
which I feel certain you all have seen.

After a glance at the question again, sorry about the knee:  yes, it
is inconvenient to have only one hand free, but only if you have to do
base, menial type things, nothing a cane-carrying gentleman would be
worried about, a definite "fashion benefit".  With a cane in your
hand, you can strut and flourish  - or hobble with dignity -  and it
keeps your hands out of your pockets, which is not considered good
style  (Father of George V or VI had his son's trouser pockets sewn
up.  Source: a book of anecdotes on British kings.)

And now the prosaic:

http://www.canesandsuch.com/history.html

http://www.phoenixmasonry.org/masonicmuseum/walking_stick_history.htm

http://www.canes.org/history.html

http://www.canescanada.com/history.htm

Here's a charming picture:
http://ejmas.com/jnc/barton-wright/barton-wright1.1.gif
Self-defence with a Walking-stick: The Different Methods of Defending
Oneself with a Walking-Stick or Umbrella when Attacked under Unequal
Conditions
Pearson?s Magazine (January 1901)
http://ejmas.com/jnc/jncart_barton-wright_0200.htm

Sorry, the picture is at
http://ejmas.com/jnc/barton-wright/barton-wright1.1.gif

The cane I can see, but what's the top hat all about, I wonder?

I couldn't resist a look into this, and though I have no answer, I did
come across this 1901 mention of the existence of both morning and
evening canes!

The article was a review of a play, "The Last of the Dandies":


"...We are shown the dandy at home, the dandy before the
looking-glass; the dandy, that is to say, at his supreme moment and in
all his glory.  We see the dressing-case...We see the barber operating
upon the dandy's curls, and told to put 'poetry' into them, to make
them 'sing'.  We see the valets...winding their master's stock round
his neck with all the solemnity of a sacred rite.  We see the
collection of coats and hats, the morning cane and the evening cane. 
During the progress of the toilette merely mundane life is suspended,
callers are hushed imperiously to silence, and even the entry of a
young man who has just saved the dandy's life only leads to a start of
horror at his ill-fitting clothes..."

I supose there might have been distinct functions for the morning cane
(stab a copy of the London Times) and the evening cane (stab an
unusually large hors d'ouvre at the club), but who knows...!

paf

"Who knows?"

Oscar Wilde would have known.