Sir - In answer to Marcus Chambers' enquiry (Flight International, 25-31 October, P37) the official publication of the Spanish air force, Revista de Aeronautica y Astronautica, has published two articles on Diego Marin Aguilera.
The first, in the December 1993 issue, tells the known facts about Aguilera, born in 1758, and his "flying device". The second article, in December 1994, focuses on the activities of the Aranda de Duera local association for the progress and diffusion of aeronautics, under the sponsorship of the Spanish air force.
The aircraft, mounted on a plinth, is a T-33 trainer donated by the Spanish air force as an additional memorial to Aguilera.
JOSE ANTONIO MARTINEZ CABEZA
Revista de Aeronautica y Astronautica
Madrid, Spain
...Diego Marin Aguilera, like Leonard da Vinci, observed the flight of birds, but he focused exclusively on the flight of eagles.
He conceived the notion that the body weight of the eagle in proportion to that of its feathers was crucial. He hunted eagles to acquire sufficient feathers to build a mechanical bird, which conformed to his observations.
On 15 May 1793, he launched his 5m (16ft)-high bird from the ruined castle above Coruna del Conde, but, after some 400m, he suffered mechanical failure and crashed. His machine was destroyed by relatives, which caused him to fall into a deep melancholy, resulting in his death at only 44 years old.
RODERICK BROMLEY
Norwich, Norfolk, UK
Source: Flight International