How does Burnham from The Devil in the White City use the World’s Fair to his advantage? Also, what details prove Burnham’s goal for the fair is different from Holmes’?

what details prove Burnham’s goal for the fair is different from Holmes’?
How does Burnham from The Devil in the White City use the World’s Fair to his advantage? Also, what details prove Burnham’s goal for the fair is different from Holmes’?
what details prove Burnham’s goal for the fair is different from Holmes’?