The Catholic Encyclopedia article you cite was written in  by most likely an elderly member of the clergy writing in standard Victorian prose form  Im sure you realize how quickly standards of prose mutated during the beginning of the th century  In any case whether or not that particular phrase is vague is rather meaningless  As I said above the simple appearance of the statement if there are antipodes indicates dissent over the shape of the eartha flat earth may or may not have antipodes but a spherical earth must have them