Her heart thumped so that she could scarcely see to go on.
"Start your machine," he said, "start your machine.

Don't keep the line waiting." This recovered her sufficiently and she went excitedly on, hardly breathing until the shadow moved away from behind her.

Then she heaved a great breath.
As the morning wore on the room became hotter.

She felt the need of a breath of fresh air and a drink of water, but did not venture to stir.
The stool she sat on was without a back or foot-rest, and she began to feel uncomfortable.

She found, after a time, that her back was beginning to ache.