Misc: What is the term called for making rings, jewellery & eyeglass hinges?

Questions

books for the bored: where does the action of _lorna doone_ take place?

sherlock holmes: this famous thriller writer was dr watson in the '32 film the sign of four?

sherlock holmes: this adventure of holmes has the most film versions?

sherlock holmes: what is the last book of holmes stories?

sherlock holmes: he is the 'most indispensible man in england' according to holmes?