What does "series of coughs" mean?

Question

Little Dorrit received a call that same evening from Mr Plornish, who, having intimated that he wished to speak to her privately, in a series of coughs so very noticeable as to favour the idea that her father, as regarded her seamstress occupation, was an illustration of the axiom that there are no such stone-blind men as those who will not see, obtained an audience with her on the common staircase outside the door.

What does the term "series of coughs" mean from the above passage in Chapter 24 Little Dorrit?

Answer 1

No great mystery here. The Cambridge dictionary defines "series" as:

a number of similar or related events or things, one following another

So in this instance, a "series of coughs" indicates a repetition of similar coughing noises, likely from the same person.

The context of the passage makes clear that this coughing is deliberate on the part of Mr Plornish in order to attract Little Dorrit's attention. This is a fairly common ploy if you want to alert someone to something without naming what it is: no one would pay attention to a single cough but by repeating the noise, bystanders are more likely to take note. Hence the "series".

User Yosef Baskin has suggested that, for clarity, it should be made clear that Mr Plornish wished to speak to her privately, but didn't want to say so out loud due to her father. He used coughing as a signal.