Thereis the wandering air；there are the motes；there are living things that blow one against another with their breath.
“This is to illustrate that the action of the p’eng is just as natural as the movement of the wandering air，or the motes.”
—Kuo Ch’ing-fan（郭庆藩）
We do not know whether the blueness of the sky is its original color，or is simply caused by its infinite height.When the p’eng sees the earth from above，just as we see the sky from below，it will stop rising and begin to fly to the south.Without sufficient depth，the water would not be able to float a large boat.Upset a cup of water into a small hole，and a mustard seed will be the boat.Try to float the cup，and it will stick，because the water is shallow and the vessel is large.Without sufficient density，the wind would not be able to support the large wings.Therefore，when the p’eng ascends to the height of ninety thousand li，the wind is all beneath it.Then，with the blue sky above，and no obstacle on the way，it mounts upon the wind and starts for the south.