In one place he gathered up very carefully a little pile of grey dust from the floor, and packed it away in an envelope.

Finally, he examined with his glass the word upon the wall, going over every letter of it with the most minute exactness.

This done, he appeared to be satisfied, for he replaced his tape and his glass in his pocket.
"They say that genius is an infinite capacity for taking pains," he remarked with a smile.

"It's a very bad definition, but it does apply to detective work." Gregson and Lestrade had watched the manoeuvres [9] of their amateur companion with considerable curiosity and some contempt.

They evidently failed to appreciate the fact, which I had begun to realize, that Sherlock Holmes' smallest actions were all directed towards some definite and practical end.
"What do you think of it, sir ?" they both asked.
"It would be robbing you of the credit of the case if I was to presume to help you," remarked my friend.