A hidden fire burns perpetually upon the hearth of the world.... In autumn this great conflagration becomes especially manifest. Then the flame that is slowly and mysteriously consuming every green thing bursts into vivid radiance. Every blade of grass and every leaf in the woodlands is cast into the great oven of Nature; and the bright colours of their fading are literally the flames of their consuming. The golden harvest-fields are glowing in the heart of the furnace.... By this autumn fire God every year purges the floor of nature. All effete substances that have served their purpose in the old form are burnt up. Everywhere God makes sweet and clean the earth with fire.