Whether the firmament divides waters from waters?

Objections

Objection 1 : It would seem that the firmament does not divide waters from waters. For bodies that are of one and the same species have naturally one and the same place. But the Philosopher says (Topic. i, 6): "All water is the same species." Water therefore cannot be distinct from water by place.
Objection 2 : Further, should it be said that the waters above the firmament differ in species from those under the firmament, it may be argued, on the contrary, that things distinct in species need nothing else to distinguish them. If then, these waters differ in species, it is not the firmament that distinguishes them.
Objection 3 : Further, it would appear that what distinguishes waters from waters must be something which is in contact with them on either side, as a wall standing in the midst of a river. But it is evident that the waters below do not reach up to the firmament. Therefore the firmament does not divide the waters from the waters.