med motives of one of the parties.
Then I work at that case until I find whether it leads to elucidation or
to some fundamental disagreement. In the latter case I reject it and
begin the process over again."

"Doesn't that method sometimes involve a good deal of wasted time and
energy?" I asked.

"No; because each time that you fail to establish a given case, you
exclude a particular explanation of the facts and narrow down the field
of inquiry. By repeating the process, you are bound, in the end, to
arrive at an imaginary case which fits all the facts. Then your
imaginary case is the real case and the problem is solved. Let me
recommend you to give the method a trial."

I promised to do so, though with no very lively expectations as to the
result, and with this, the subject was allowed, for the present, to
drop.

Chapter XII

The Portrait

The state of mind which Thorndyke had advised me to cultivate was one
that did not come easily. However much I endeavoured to shuffle the
facts of the Blackmore case, there was one which inevitably turned up on
the top of the pack. The circumstances surrounding the execution of
Jeffrey Blackmore's will intruded into all my cogitations on the subject
with hopeless persistency. That scene in the porter's lodge was to me
what King Charles's head was to poor Mr. Dick. In the midst of my
praiseworthy efforts to construct some intelligible scheme of the case,
it would make its appearance and reduce my mind to instant chaos.

For the next few days, Thorndyke was very much occupied with one or two
civil cases, which kept him in court during the whole of the sitting;
and when he came home, he seemed indisposed to talk on professional
topics. Meanwhile, Polton worked steadily at the photographs of the
signatures, and, with a view to gaining experience, I assisted him and
watched his methods.

In the present case, the signatures were enlarged from their original
dimensions--rather less than an inch and a half in length--to a length
of four and a half inches; which rendered all the little peculiarities
of the handwriting surprisingly distinct and conspicuous. Each signature
was eventually mounted on a slip of card bearing a number and the date
of the cheque from which it was taken, so that it was possible to place
any two signatures together for comparison. I looked over the whole
series and very carefully compared those which showed any differences,
but without discovering an