 Although not a success, their development was the basis of Burney's later invention of the paravane.Dennistoun Burney was a naval officer who had become convinced of the possibilities of naval aviation and who had a number of technical ideas on the subject.Wanting to develop these but lacking the technical resources to do so, he approached Bristol who expressed an interest and, having been assured of support from the Admiralty, set up a highly secret separate design office, called the X Department, to develop these at the end of 1911.