When we're looking for stolen watches we often come across the works, and it's not possible to identify wheels and springs out of a heap; but it's not often that we come across cases that are wanted.
Now, in the present instance much will depend on whether the thief is a good man--that's what they call a man who knows his work.

A first-class crook will know whether a thing is of more value than merely the metal in it; and in such case he would put it with someone who could place it later on--in America or France, perhaps.

By the way, do you think anyone but yourself could identify your lamps ?" "No one but myself!" "Are there others like them ?" "Not that I know of," answered Mr.Corbeck; "though there may be others that resemble them in many particulars." The Detective paused before asking again: "Would any other skilled person--at the British Museum, for instance, or a dealer, or a collector like Mr.Trelawny, know the value--the artistic value--of the lamps ?" "Certainly! Anyone with a head on his shoulders would see at a glance that the things were valuable." The Detective's face brightened.

"Then there is a chance.

If your door was locked and the window shut, the goods were not stolen by the chance of a chambermaid or a boots coming along.