Events such as those of today illustrate that the deuctive reasoning
employed by Mr. Sherlock Holmes are not merely limited to
postcognition, but itself could be employed to prevent a crime from
even occuring.  I was with Holmes who was upon an errand to the house
of Lord Coverdale to confir the authenticity of a recently accquired
Strad. Following such, Coverdale enjoyed libations with us.  It was
shortly after filling our glasses a second time that the bell rang
and the doorman presented us with a Mr. John Islington,
Comptroller [?Treasurer] of the Bank of London.

"My Lord," he said, "I request to speak to you regarding an affair of
yours that requires some discretion."

Coverdale provided the guest with a seat and a cordial.  "These are
trusted friends," he said, gesturing to Holmes and myself, "Whatever
it may be, you may speak freely in front of them."

"As you wish," said the banker, "While there have been subsantial
charges may against your account in the past several days--"

"I am aware of them," Coverdale interjected.

"--your balanced has diminished, and, indeed, fallen into debt,"
the guest continued, "Of course, the bank appreciates your business
and will go to lengths to keep your account in good standing, it is
not our policy even for a Lord to allow a deficit to be run without a
formal loan agreement."

"Impossible," said Coverdale, "I posted two deposits last week."

"They were never received," said the banker, "Our last recorded
deposit in your name is dated ... twenty-eight days ago.  If you have
available..." He looked at a ledger and continued, "One thousand, two
hundred and thirteen pounds sterling, or more if you desire, I'd be
happy to transport it to the bank and credit it immediately to your
account before future expenses -- already in processing, I must add --
must, I fear, be rejected for insufficient funds, and so thereby any
embarassment to all parties may be avoided."

"How peculiar," said Coverdale, opening his wallet, "But I suppose it
is the thing to do."

But Holmes stayed the lord's and. "Less peculiar," Holmes said, "Than
nefarious. While you'll notice his shirt is, indeed, the shirt of a
bank officer and freshly cleaned and starched, despite and indeed
illuinated thereby you can see even in parlour light crimped verticle
wrinkles that could only be caused by the wearing of a cheap leather
belt of a lower classed worker.  While his shirt is pressed and white,
it is the one garment whose inadequacy would immediately be noticed in
his guise.  I will wager you will find his jacket and trousers not
quite to fit and, indeed, used, although lightly.  He is not wearing
braces, those being never found in good condition at used clothiers,
and has worn a belt perhaps as recently as his journey here.  While I
do not know for fact, I would suppose there is a John Islington
employed as comptroller and that this man is his underling, perhaps a
valet but more likely a clerk at the bank, who has gained illegitimate
access to your financial records."

When further inspection and pursuit of knowledge had, as inevitably,
proven Holmes' deductions to be factual, we left following the
impersonator's arrest and profound exhibitions of gratitude by Lord
Coverdale. I asked, as I so often must, a question of Holmes, "I
understand your reasoning about the wrinkles, but what drew your
attention to his shirt in the first place, outside of your customary
skepticism?"

"Elementary, dear Watson," Holmes replied, "While not all gentlement
wear well-fitted clothing, one whose clothes are ill-fitted bear a
closer look."