Montigny mitrailleuse
The Montigny mitrailleuse was an early type of crank-operated machine-gun developed by the Belgian gun works of Joseph Montigny between 1859 and 1870. It was an improved version of the "Mitrailleuse", () invented by Belgian Captain Fafschamps in 1851 which was a fixed 50-barrelled volley gun.
Aileron
There are still conflicting claims today over who first invented the aileron. Other 19th century engineers and scientists, including Charles Renard, Alphonse Pénaud, and Louis Mouillard, had described similar flight control surfaces, possibly serving as further inspiration to Boulton aside from Count d'Esterno. Another technique for lateral flight control, wing warping, was also described or experimented with by several people including Jean-Marie Le Bris, John Montgomery, Clement Ader, Edson Gallaudet, D.D. Wells, and Hugo Mattullath. Aviation historian C.H. Gibbs-Smith wrote that the aileron was "...one of the most remarkable inventions... of aeronautical history, which was immediately lost sight of".