The creation of two Swiss-borne gunsmiths; eccentric engineer and inventor of the cartridge breech-loader (patented 1812), Jean Pauly, and Durs Egg, gun-maker to King George III – its construction was begun during June 1816 in Knightsbridge, London, and continued into the following year. The rigid craft, Pauly’s second dirigible flying fish – his first being a smaller one that he first flew in 1804 near Paris with little success – had an envelope 90 feet long and was notable for its intended use of trimmable ballast. The device, to have been either a sand-filled box or a water-filled barrel (accounts differ), was to be slung on ropes laid out between the airship’s tail and the rear of the gondola, and by using these ropes the ballast could then be hauled back and forth, thus moving the centre of gravity of the aerostat. For this, and its other innovations in aeronautic navigability, a patent, No.3909 dated April 15, 1815, was granted by the Great Britain Patent Office to Jean Samuel Pauly and Durs Egg. This patent became entangled in a lawsuit between the two gunsmiths, which was ostensibly about pistols. The lawsuit, Egg v. Pauly, lasted from 1817 until 1820 – the year previous to Pauly’s death. During the lawsuit Pauly claimed that Egg had failed to assist with the production of certain firearms in contravention of an agreement dated March 15, 1815, which dealt with the building of the airship. In the end, the venture, aptly named “Egg’s Folly” by those following its lack of progress, failed miserably, proving to be both too complex and too costly, resulting in the financial ruin of its inventors. A decade later, Durs Egg, having gone blind and insane, died in 1831. In January 1844, P. T. Barnum and General Tom Thumb (1838-1883) sailed for England to begin a European tour where at the Surrey Zoological Gardens a captive balloon ascent exhibition was made by the famous dwarf using the Dolphin’s still-existing goldbeater’s skin air bladder, or ballonet rather, capable of lifting fifty or sixty pounds when filled with gas.

In 1789, Baron Scott, of Paris, proposed an aeronautic fish. Jean Samuel Pauly revived the plan with modifications. Marshal Michel Ney patronised it, and gave nearly 100,000 francs for the construction of an aerostat 50 feet long, and for experiments. Its first trial was made on August 22, 1804 at Sceaux, south of Paris; the success anticipated did not follow.