The spiral in a snail's shell is the same mathematically as the spiral in the Milky Way galaxy and it's also the same mathematically as the spirals in our DNA. It's the same ratio that you'll find in very basic music that transcends cultures all over the world.
Books constitute capital. A library book lasts as long as a house for hundreds of years. It is not then an article of mere consumption but fairly of capital and often in the case of professional men setting out in life it is their only capital.
