I don’t know what you may have said to him, or what you may say hereafter; but I should like you to know that if you have encouraged him to believe that he will gain anything by hanging on, or that I have budged a hair’s-breadth from the position I took up a year ago, you have played him a trick for which he may exact reparation.
There are no more uses of "breadth" in the book.
Show samples from other sources
The introductory courses are meant to add to breadth rather than depth of understanding.
a teacher must have a breadth of knowledge of the subject