"All knowledge comes useful to the detective," remarked Holmes.
"Even the trivial fact that in the year 1865 a picture by Greuze
entitled La Jeune Fille a l'Agneau fetched one million two
hundred thousand francs--more than forty thousand pounds--at the
Portalis sale may start a train of reflection in your mind."

It was clear that it did. The inspector looked honestly
interested.

"I may remind you," Holmes continued, "that the professor's
salary can be ascertained in several trustworthy books of
reference. It is seven hundred a year."

"Then how could he buy--"

"Quite so! How could he?"

"Ay, that's remarkable," said the inspector thoughtfully. "Talk
away, Mr. Holmes. I'm just loving it. It's fine!"

Holmes smiled. He was always warmed by genuine admiration--the
characteristic of the real artist. "What about Birlstone?" he
asked.

"We've time yet," said the inspector, glancing at his watch.
"I've a cab at the door, and it won't take us twenty minutes to
Victoria. But about this picture: I thought you told me once,
Mr. Holmes, that you had never met Professor Moriarty."

"No, I never have."