Codex on the Flight of Birds of a kite as seeking a wind current. When the winds are high, one will see the bird very high in the sky, but when the winds are low, the bird stays closer to the ground. Leonardo describes how a bird rests in the air, after flapping its wings to gain altitude, by gliding downward to the ground. Folio 6 contains multiple diagrams of birds flying and their bone structure, and all of the commentary is on flight and how birds fly the way that they do. Leonardo starts off by describing how a bird ascends or descends in different
Rock Eagle depicts a bird with a large beak and a fan tail. Archeologist Charles C. Jones produced the earliest measurements in 1877. It measures 120 feet from head to tail and 102 feet from wingtip to wingtip. The bird's head is often described as being turned to the east (see "Marker") "to face the rising sun", perhaps to suggest a cosmological significance to its placement. However, the bird's head actually faces south by southeast, and its beak points almost due south. The rocks comprising the bird's chest are piled eight to ten feet high, while the wings, tail, and head rise