Thoreau mostly uses imagery to illustrate time in the excerpt. The second sentence is saying that he is in the midst of time/living, and he can "detect how shallow it is," meaning that he is aware that life is short and that the end is inevitable. Thoreau also describes time as being fleeting, but ever-present.
I hope this helps!
What play is this about??
Answer : C) It summarizes the main topic of the essay
In the beginning of the book it is kinda tense/ intense.<span>The entire period from the time he wakes up until Grete's violin solo and his death is one long battle to adjust to his new body </span>