Present perfect in a past-tense context

Question

Presently I heard Pilot bark far below, out of his distant kennel in the courtyard: hope revived. Nor was it unwarranted: in five minutes more the grating key, the yielding lock, warned me my watch was relieved. It could not have lasted more than two hours: many a week has seemed shorter.
Mr. Rochester entered, and with him the surgeon he had been to fetch.
(Jane Eyre)

The sentence with the highlighted part is using the present perfect tense; yet, the previous and the next ones use the simple past tense. What's the reason for that?

Answer 1

Jane here compares her experience of the particular past event with all the experiences of her life.

A couple of reasons which occur to me, more or less asking myself what reading the passage made me feel:

• Perhaps Brontë wishes to make it clear, unobtrusively, that the comparison is not something which crossed Jane's mind at the time.
• Perhaps she wishes to communicate that the moment was one which still stands out in Jane's mind as exceptional.
• Perhaps she has just entered into the part and come up, unconsciously, with one of those unemphatic moments of self-deprecating humour which make Jane such an attractive character.

The last seems likeliest to me, because that's how stories get told: by inspiration (or accident, if you prefer) rather than by contrivance. Brontë wrote Jane Eyre in the last generation before literature at the peak of the cultural pyramid became technologized: it was published the year after Poe's essay ‘The Philosophy of Composition’.

Answer 2

If she had written "many a week had seemed shorter", it would be a comparison to all the weeks Jane had ever experienced up to this point in the story.

However, she wrote has instead. To me, this sounds like Brontë is making a general statement; the author isn't just comparing it to Jane's personal experiences up to this point, but to how long weeks seem in general.