Знак четырех
I. The Science of Deduction
Here,too,isacuriouslittleworkupontheinfluenceofatradeupontheformofthehand,withlithotypesofthehandsofslaters,sailors,corkcutters,compositors,weavers,anddiamond-polishers.Thatisamatterofgreatpracticalinteresttothescientificdetective,—especiallyincasesofunclaimedbodies,orindiscoveringtheantecedentsofcriminals.ButIwearyyouwithmyhobby.”
“Notatall,”Ianswered,earnestly.“Itisofthegreatestinteresttome,especiallysinceIhavehadtheopportunityofobservingyourpracticalapplicationofit.Butyouspokejustnowofobservationanddeduction.Surelytheonetosomeextentimpliestheother.”
“Why,hardly,”heanswered,leaningbackluxuriouslyinhisarm-chair,andsendingupthickbluewreathsfromhispipe.“Forexample,observationshowsmethatyouhavebeentotheWigmoreStreetPost-Officethismorning,butdeductionletsmeknowthatwhenthereyoudispatchedatelegram.”
“Right!”saidI.“Rightonbothpoints!ButIconfessthatIdon’tseehowyouarrivedatit.Itwasasuddenimpulseuponmypart,andIhavementionedittonoone.”
“Itissimplicityitself,”heremarked,chucklingatmysurprise,—“soabsurdlysimplethatanexplanationissuperfluous;andyetitmayservetodefinethelimitsofobservationandofdeduction.Observationtellsmethatyouhavealittlereddishmouldadheringtoyourinstep.JustoppositetheSeymourStreetOfficetheyhavetakenupthepavementandthrownupsomeearthwhichliesinsuchawaythatitisdifficulttoavoidtreadinginitinentering.
