watching caught sight of the number on our door, and ran rapidly across
the roadway. We heard a loud knock, a deep voice below, and heavy steps
ascending the stair.

"For Mr. Sherlock Holmes," he said, stepping into the room and handing
my friend the letter.

Here was an opportunity of taking the conceit out of him. He little
thought of this when he made that random shot. "May I ask, my lad," I
said, in the blandest voice, "what your trade may be?"

"Commissionaire, sir," he said, gruffly. "Uniform away for repairs."

"And you were?" I asked, with a slightly malicious glance at my
companion.

"A sergeant, sir, Royal Marine Light Infantry, sir. No answer? Right,
sir."

He clicked his heels together, raised his hand in a salute, and was
gone.

CHAPTER III. THE LAURISTON GARDEN MYSTERY [6]

I CONFESS that I was considerably startled by this fresh proof of the
practical nature of my companion's theories. My respect for his powers
of analysis increased wondrously. There still remained some lurking
suspicion in my mind, however, that the whole thing was a pre-arranged
episode, intended to dazzle me, though what earthly object he could have
in taking me in was past my comprehension. When I looked at him he
had finished reading the note, and his eyes had assumed the vacant,
lack-lustre expression which showed mental abstraction.

"How in the world did you deduce that?" I asked.

"Deduce what?" said he, petulantly.

"Why, that he was a retired sergeant of Marines."

"I have no time for trifles," he answered, brusquely; then with a smile,
"Excuse my rudeness. You broke the thread of my thoughts; but perhaps
it is as well. So you actually were not able to see that that man was a
sergeant of Marines?"

"No, indeed."

"It was easier to know it than to explain why I knew it. If you
were asked to prove that two and two made four, you might find some
difficulty, and yet you are quite sure of the fact. Even across the
street I could see a great blue anchor tattooed on the back of the
fellow's hand. That smacked of the sea. He had a military carriage,
however, and regulation side whiskers. There we have the marine. He was
a man with some amount of self-importance and a certain air of command.
You must have observed the way in which he held his head and swung
his cane. A steady, respectable, middle-aged man, too, on the face of
him--all facts which led me to believe that he had been a sergeant."

"Wonderful!"