All place names in Charlotte Brontë's The Professor appear to be obscured. A few examples from the novel's first chapter:
That gentleman and Lord T. knew well enough that the Crimsworths were an unscrupulous and determined race; they knew also that they had influence in the borough of X——; and, making a virtue of necessity, they consented to defray the expenses of my education.
...
I asked, moreover, if he could give me employment. His answer expressed no approbation of my conduct, but he said I might come down to ——shire, if I liked, and he would ‘see what could be done in the way of furnishing me with work.’ I repressed all—even mental comment on his note—packed my trunk and carpet-bag, and started for the North directly.
...
“After two days’ travelling (railroads were not then in existence) I arrived, one wet October afternoon, in the town of X——.
Why is that? Is this peculiarity specific to Brontë, or a wider convention?