Swift's Travels into Several Remote Nations of the World. By Lemuel Gulliver (1726), a satire of eighteenth-century British society and traveler's stories (which were very popular in England), has four settings, each tied to one of Dr. Gulliver's four voyages.
When Gulliver's ship is wrecked during his first voyage, he washes up on the beach in the land of Lilliput, where everyone (except Gulliver) is about six inches tall. Gulliver eventually becomes a nobleman of Lilliput, initially helps the Lilliputians defeat the Blefuscans, their arch enemies, and then assists in negotiating a peace treaty between the two countries. While touring the island of Blefuscu, Gulliver finds his wrecked boat, and with the help of the Blefuscans, refits the boat and is eventually picked up by an English ship and returned to England.
On his second voyage, Gulliver lands on the coat of Great Tartary, wanders away from the English landing party, and is captured by the Brobdingnagians, who are about fifty or sixty feet tall. After being kept by a young girl as a curiosity, Gulliver ends up in the Brobdingnagian court where the king becomes thoroughly disgusted by Gulliver's account of eighteenth-century British politics and culture. Gulliver eventually escapes from Brobdingnag but is marooned by Chinese pirates on the island of Laputa.
Gulliver's third voyage (Laputa) allows Swift to satirize the scientific community in Great Britain. The Laputans, who are all scientists, carry out experiments that have no practical value to the larger society: trying to soften marble in order to make pillows; attempting to build houses and other buildings from the top down; and training spiders to replace silkworms to create silk. The Laputans spend so much time thinking about science that they need servants to slap them with balloons to get their attention on everyday life--eating, for example.
The fourth voyage to the land of the Houyhnhnms, a country governed by intellectual horses and where humans are animals known as "Yahoos," gives Swift the opportunity to criticize humanity. Swift, in the persona of Gulliver, argues, for example, that mankind should be, but is not, governed by reason and that man allows the lowest part of his nature--lust and violent emotions--to govern his nature. Swift uses the Houyhnhnms to represent what mankind could be if mankind were ruled by reason, and the Yahoos, who are violent and ungovernable, are unmistakeably men. When Gulliver returns to England, he is so alienated from men that he spends as much time as possible with horses.
The four settings of Gulliver's voyages provide Swift with the opportunity to discuss everything he feels is wrong with mankind in general and British society specifically.