From the Viridarium of Francisco de Mendoca to the Airship of Cypriano Jardim

摘要

In his most acclaimed work - the Viridarium - first published in 1631, the Portuguese Jesuit named Francisco de Mendoca presented an early discussion of the problem whether the air would be, at least in some part, navigable. Based on the writings of Aristotle, as well as on the doctrine that fire is lighter than air, he concluded that as water is navigable where it is bounded by air, the latter must also be navigable where it is contiguous to fire. Only a few decades later, these ideas would influence the endeavors of Bartholomeu Lourenco de Gusmao in aerostation. Several contemporary accounts described his use of inflammable materials to accomplish the ascent of model hot-air balloons in Lisbon. His intent to build a full-scale flying machine was promptly sanctioned by the King of Portugal, but the inventor would ultimately fail to unravel the problem of scale-up with the resources available in 1709. Later success by the Montgolfier brothers sparked renewed interest of Portuguese scholars and inventors in aerostation. Following reports of foreign advances in the development of lighter-than-air, powered, steerable flying machines, Portuguese military officer Cypriano Pereira Jardim presented a project of an airship to the Royal Academy of Sciences (Lisbon) in 1885. By proposing the use of an electric-powered swiveling propeller, he intended to suppress the need of venting lifting gas and carrying ballast, so that the range of an airship could be significantly increased. The original design was subsequently improved for higher maneuverability via minimization of the turning radius. Years later, the construction of the dirigible started at Lachambre's factory in Paris, but it would remain unfinished due to lack of funding.