Language evolves. Words do not retain the same meanings which they had centuries before, making things like the writings of Shakespeare difficult to be understood by later generations.

But as words change in meaning, they usually do not do so abruptly. This produces a communication difficulty when the writer or speaker is using a word in one sense and the reader or hearer thinks the source meant a different meaning.

Transpire is a word which is in this intermediate stage. When the word is used literally it still retains the same meaning it had two centuries ago. However, when it is used in its figurative sense the 21st century usage is often different from its traditional meaning.

This causes a comprehension problem when reading a public domain book from before 1923. Many writers of a century ago, still used the traditional meaning which was "it came to be known" or "as it was discovered."

However, the reader of today expects it to mean "as it happened to occur." This causes confusion in the reader's mind when he or she comes across a passage in which the writer states that after a private event occurred several days passed before it transpired or that it never became known to others.

An example of this is the passage:

"What actually passed between them has not yet transpired, but it is said
that for half-an-hour there had been nothing to indicate to the other
occupants of the house that anything unusual was in progress when
suddenly two shots rang out in rapid succession."

That passage occurs in:

The writer meant "What actually passed between them has not yet" come to be known by other people. The writer was using the word according to its traditional meaning and not the way many people use that word today.

I was reminded of this by an article that I read today about the affect of forests on climate which uses the literal meaning of the word "transpire."

This article contains the following sentence:

Moreover, when plants transpire, they cool Earth’s surface and warm the
air, just as the evaporation of sweat cools your body on a hot day.

The writer did not mean "when plants occur" but rather when plants emit moisture which they do in a manner analogous to the way we perspire.

Words like perspire, inspire, respiration, and transpire share a common heritage in their root word but most of us who speak english do not consider the roots of the words which we use and many simply do not care.