Turn of the Screw

Henry James entitled a novella, The Turn of the Screw. What's does that expression mean?

[Tdol]

It can mean a slow increase in pressure.

[MrPedantic]

Yes; if you look on the first page, you'll see that the character Douglas uses the phrase:

1. "...the child gives the effect another turn of the screw..."

i.e. "the fact that the ghost appeared to a little boy gives the story another twist, another increase in literary pressure."

Near the end, interestingly, the governess herself uses the phrase:

2. "...another turn of the screw of ordinary human virtue".

Here, the sense is slightly different: the governess means she must screw up her courage (i.e. tighten it, like a screw, so it doesn't slip) to face the ordeal.

Cf. Lady Macbeth's words to Macbeth: "screw your courage to the sticking-place, And we'll not fail."

All the best,

MrP