Genesis 6:15

Three hundred cubits, &c. The ark, according to the dimensions here set down, contained four hundred and fifty thousand square cubits; which were more than enough to contain all the kinds of living creatures, with all necessary provisions: even supposing the cubits here spoken of to have been only a foot and a half each, which was the least kind of cubits. (Challoner) --- It is therefore unnecessary for us to have recourse, with Cappel, to the sacred cubit, which was twice as large as the common one, but which seems not to have been in use among the Jews before the Babylonian captivity. Still less need we adopt the geometrical cubit, which contains six ordinary ones, as we might be authorised to do by the great names of Origen and St. Augustine, City of God xv. 27. q. in Gen. i. 4. These dimensions would make the ark as large as a city. Moses always speaks of the same sort of cubit, used probably in Egypt. Apelles and other heretics, with some modern infidels, have attempted to shew, that this account of Moses is fabulous. But they have been amply refuted by able calculators, John Buteo, Pelletier, &c. This amazing structure, for which God himself gave the plan, was divided with three stories, besides the lower part of the vessel, which might serve to keep fresh water. The different species of animals are not so numerous, as some imagine. Fishes, and such creatures as can live in water, would not need to come into the ark. Animals deprived of exercise, and allowed barely what may support nature, will live upon a very little. Even an ox, according to Columella, will live on 30 pounds of hay, or on a cubic foot, a whole day, so that 400 of these large creatures might be supported on 146,000 cubic feet. The middle story, for provisions, would alone contain 150,000 cubits. Noe's family, and the birds, would probably occupy the room above, in which was a window all around, of the height of a cubit, without glass or crystal, which were not yet invented, but defended with lattice work of wood, like our dairy rooms. (Haydock)