The growth of the earth, and prose on the sea monster
A pot experiment proving the earth's growth, and a literary apostrophe to a whale-like ocean monster
Under the heading 'Examples and proofs of the growth of the earth,' Leonardo argues that soil continually increases as generations of plants germinate, seed, die and rot back into it, so that over ten years and a thousand years the earth's mass measurably grows. He answers the objection that potted soil sinks, then points to mountains where the growing earth buries ancient city walls and where living stone has swallowed a leaning column, leaving its fluted form. Written with the sheet inverted, a second passage is a literary apostrophe to a huge ocean creature seen 'in the guise of a mountain,' its bristly black back furrowing the swollen sea.
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Proofs of the growth (accretion) of the earth
Leonardo proposes measuring the increased soil after ten years, and multiplying to a thousand, to show 'how much the world's earth has grown.' In the high mountains the walls of ancient ruined cities are occupied and hidden by the earth's growth, and on rocky peaks the living stone has, over long time, swallowed a leaning column, leaving in the rock its fluted form.
The pot of earth left on a roof
Fill a pot with pure earth and set it on a roof; it will at once sprout leafy grasses that grow, seed and drop their offspring at the feet of the old plants. The dried grasses fall back, turn into the soil and give it growth, and the new seeds repeat the same course, each dying and rotting into fresh nourishing humour.
Apostrophe to the great ocean monster
In repeated exclamations Leonardo addresses a creature seen 'how many times' amid the waves of the swollen and great Ocean, 'in the guise of a mountain' with a bristly and black back, moving with grave and proud bearing to overcome and overwhelm the sea waters.
