 392 of 1868, issued about 35 years before ailerons were "reinvented" in France, became forgotten and lost from sight until after the flight control device was in general use.Gibbs-Smith stated on several occasions that if the Boulton patent had been revealed at the time of the Wright brothers' legal filings, they might not have been able to claim priority of invention for the lateral control of flying machines.The fact that the Wright brothers were able to gain a patent in 1906 did not invalidate Boulton's lost and forgotten invention.