Read the quote bracketed thus:
Excellent men[, who had been forced all their lives to spell on an impromptu-phonetic system, and having carried on a successful business in spite of this disadvantage, had acquired money enough to give their sons a better start in life than they had had themselves,] must necessarily take their chance as to the conscience and the competence of the schoolmaster whose circular fell in their way, and appeared to promise so much more than they would ever have thought of asking for, including the return of linen, fork, and spoon.
(The Mill on the Floss, George Eliot, p 168)
Incidentally, I absolutely adore The Mill on the Floss. I think it as good as Middlemarch and I'd loved to discuss it with anyone.