Plate 7 - An extravagant book

Plate 7 of the book edited by Rafael Jover (Granada, 1845 - ¿?, 1896) in 1878, from the manuscript "New system of air navigation...", dated 1762 and written by Santiago de Cárdenas (Callao, 1726 - Lima, 1766).
This book contains the plate that includes a tradition by Ricardo Palma entitled "Santiago Volador", a resume of the aforementioned manuscript, and the dissertation by Cosme Bueno (Aragón, 1711 - Lima, 1798), an erudite cosmographer of the time who dismissed Cardenas' work.
The image, taken from the original drawing by the author of the manuscript, shows a person lying on a surface and watching the flight of the birds.