History
The Nautilium Shell was a unique weapon that required Attuma's men to scour the oceans for enough Nautilium to make the weapon. It was fired by a monstrous cannon that was dozens of ft long and high. The shell would have exploded in the upper atmosphere, fusing with the oxygen. It would have changed the density of the oxygen, making it most enough for Homo mermanus to live on the surface. Humans in turn would find it difficult to breathe without special helmets provided by Attuma, making them their slaves.[1]