Which setting detail establishes the time period and advances the action?

the inkwell

Explanation:

if your referring to this...

The only room visible in the KELLER house is ANNIE’S, where by lamplight ANNIE in a shawl is at a desk writing a letter; at her bureau HELEN in her customary unkempt state is tucking her doll in the bottom drawer as a cradle, the contents of which she has dumped out, creating as usual a fine disorder.

ANNIE mutters each word as she writes her letter, slowly, her eyes close to and almost touching the page, to follow with difficulty her penwork.

ANNIE: ". . . and, nobody, here, has, attempted, to, control, her. The, greatest, problem, I, have, is, how, to, discipline, her, without, breaking, her, spirit.”

(Resolute voice) "But, I, shall, insist, on, reasonable, obedience, from, the, start—”

(At which point HELEN, groping about on the desk, knocks over the inkwell. ANNIE jumps up, rescues her letter, rights the inkwell, grabs a towel to stem the spillage, and then wipes at HELEN’S hands. . . .)