Note l — BOOK IV. (continued 2)

The Feathers being placed from the Head towards the Tail, in close and neat Order, and withal preened and dressed by the Contents of the Oil-Bag, afford as easie a Passage through the Air, as a Boat new cleaned and dressed finds in its Passage through the Waters. Whereas, were the Feathers placed the contrary, or any other way (as they would have been, had they been placed by Chance, or without Art) they would then have gathered Air, and been a great Encumbrance to the Passage of the Body through the Air. See Book VII. Chap. 1. Note (b).