Jonathan Swift is very conscious of creating a sense of legitimacy around Gulliver’s Travels.  As we saw from the original cover of the book, Swift didn’t want to distinguish his work from other factual accounts of travel that were being published around the time.  In the early 18^th century, written works were virtually always used to document factual information, but Swift wanted to unsettle his readers by creating a piece of writing that seemed very terrestrial but quickly spiralled into an entirely bizarre world.  Gulliver is very insistent at the end of every voyage that what he is telling you is the unabashed truth, as though he is making sure the reader is sufficiently confused.  He describes the wonders of a group of people that hit each other in the face with balloons because they have the attention span of a house fly, and then reiterates that he is completely serious.  Readers would have begun the book expecting some sincere story of travel, and almost immediately been forced to falter in their beliefs.  A legitimate book that unapologetically segues into such an outlandish subject makes readers unsure of how they are supposed to react, which was what Swift intended.  He wanted people to question the truth and falter in their beliefs, an effect which is amplified by the scarcity of a point of reference for a fictional story.