Jules Verne

“ In business, Ned, but not in mathematics. Listen to me. Let's accept that the pressure of one atmosphere is represented by the pressure of a column of water thirty-two feet high. In reality, such a column of water wouldn't be quite so high because here we're dealing with salt water, which is denser than fresh water. Well then, when you dive under the waves, Ned, for every thirty-two feet of water above you, your body is tolerating the pressure of one more atmosphere, in other words, one more kilogram per each square centimeter on your body's surface. ”

“ I believe in the existence of a mammal with a powerful constitution, belonging to the vertebrate branch like baleen whales, sperm whales, or dolphins, and armed with a tusk made of horn that has tremendous penetrating power."
"Humph!" the harpooner put in, shaking his head with the attitude of a man who doesn't want to be convinced.
"Note well, my fine Canadian," I went on, "if such an animal exists, if it lives deep in the ocean, if it frequents the liquid strata located miles beneath the surface of the water, it needs to have a constitution so solid, it defies all comparison." ”

“ Ned put in.
"All right then, my fine harpooner, if vertebrates several hundred meters long and proportionate in bulk live at such depths, their surface areas make up millions of square centimeters, and the pressure they undergo must be assessed in billions of kilograms. Calculate, then, how much resistance of bone structure and strength of constitution they'd need in order to withstand such pressures!"
"They'd need to be manufactured," Ned Land replied, "from sheet-iron plates eight inches thick, like ironclad frigates." ”