“And how？” I asked involuntarily.
“Well， I have a trade of my own. I suppose I am the only one inthe world. I’m a consulting detective， if you can understand whatthat is. Here in London we have lots of Government detectivesand lots of private ones. When these fellows are at fault， theycome to me， and I manage to put them on the right scent. Theylay all the evidence before me， and I am generally able， by the helpof my knowledge of the history of crime， to set them straight.
There is a strong family resemblance about misdeeds， and if youhave all the details of a thousand at your finger ends， it is odd ifyou can’t unravel the thousand and first. Lestrade is a well-knowndetective. He got himself into a fog recently over a forgery case，and that was what brought him here.”
“And these other people？”
“They are mostly sent on by private inquiry agencies. They areall people who are in trouble about something and want a littleenlightening. I listen to their story， they listen to my comments，and then I pocket my fee.”
“But do you mean to say，” I said， “that without leaving yourroom you can unravel some knot which other men can makenothing of， although they have seen every detail for themselves？”
“Quite so. I have a kind of intuition that way. Now and againa case turns up which is a little more complex. Then I have tobustle about and see things with my own eyes. You see I have alot of special knowledge which I apply to the problem， and whichfacilitates matters wonderfully. Those rules of deduction laiddown in that article which aroused your scorn are invaluable tome in practical work. Observation with me is second nature. Youappeared to be surprised when I told you， on our first meeting，that you had come from Afghanistan.”
“You were told， no doubt.”
“Nothing of the sort. I knew you came from Afghanistan.
From long habit the train of thoughts ran so swiftly through mymind that I arrived at the conclusion without being consciousof intermediate steps. There were such steps， however. Thetrain of reasoning ran， ‘Here is a gentleman of a medical type，but with the air of a military man. Clearly an army doctor， then.
He has just come from the tropics， for his face is dark， and thatis not the natural tint of his skin， for his wrists are fair. He hasundergone hardship and sickness， as his haggard face says clearly.
His left arm has been injured. He holds it in a stiff and unnaturalmanner. Where in the tropics could an English army doctorhave seen much hardship and got his arm wounded？ Clearly inAfghanistan.’ The whole train of thought did not occupy a second.
I then remarked that you came from Afghanistan， and you wereastonished.”
“It is simple enough as you explain it，” I said， smiling. “Youremind me of Edgar Allen Poe’s Dupin. I had no idea that suchindividuals did exist outside of stories.”
Sherlock Holmes rose and lit his pipe. “No doubt you thinkthat you are complimenting me in comparing me to Dupin，” heobserved. “Now， in my opinion， Dupin was a very inferior fellow.
That trick of his of breaking in on his friends’ thoughts with anapropos remark after a quarter of an hour’s silence is really veryshowy and superficial. He had some analytical genius， no doubt；but he was by no means such a phenomenon as Poe appeared toimagine.”
“Have you read Gaboriau’s works？” I asked. “Does Lecoq comeup to your idea of a detective？”
Sherlock Holmes sniffed sardonically. “Lecoq was a miserablebungler，” he said， in an angry voice； “he had only one thing torecommend him， and that was his energy. That book made mepositively ill. The question was how to identify an unknownprisoner. I could have done it in twenty-four hours. Lecoq took sixmonths or so. It might be made a textbook for detectives to teachthem what to avoid.”
I felt rather indignant at having two characters whom I hadadmired treated in this cavalier style. I walked over to the window，and stood looking out into the busy street. “This fellow may bevery clever，” I said to myself， “but he is certainly very conceited.”
“There are no crimes and no criminals in these days，” he said，querulously. “What is the use of having brains in our profession？ Iknow well that I have it in me to make my name famous. No manlives or has ever lived who has brought the same amount of studyand of natural talent to the detection of crime which I have done.
And what is the result？ There is no crime to detect， or， at most，some bungling villany with a motive so transparent that even aScotland Yard official can see through it.”
I was still annoyed at his bumptious style of conversation. Ithought it best to change the topic.
“I wonder what that fellow is looking for？” I asked， pointing toa stalwart， plainly dressed individual who was walking slowly downthe other side of the street， looking anxiously at the numbers. Hehad a large blue envelope in his hand， and was evidently the bearerof a message.
“You mean the retired sergeant of Marines，” said Sherlock Holmes.
“Brag and bounce！” thought I to myself. “He knows that Icannot verify his guess.”
The thought had hardly passed through my mind when the manwhom we were watching caught sight of the number on our door，and ran rapidly across the roadway. We heard a loud knock， a deepvoice below， and heavy steps ascending the stair.
“For Mr. Sherlock Holmes，” he said， stepping into the room andhanding my friend the letter.
Here was an opportunity of taking the conceit out of him. Helittle 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 mycompanion.
“A sergeant， sir， Royal Marine Light Infantry， sir. No answer？
Right， sir.”
He clicked his heels together， raised his hand in salute， and wasgone.
The Lauriston Garden Mystery