What literary work of the 18th century mentions Mars as having two moons about 150 years before they were discovered?

Irish clergyman and social and political commentator, best known for his satirical fantasy Gulliver's Travels, originally entitled Travels into Several Remote Nations of the World in Four Parts by Lemuel Gulliver (1726), in which reference is made to two (then undiscovered) moons of Mars. The astronomers on the flying island of Laputia, says Gulliver, have discovered two lesser stars, or satellites, which revolve around Mars, whereof the innermost is distant from the center of the primary exactly three of his diameters, and the outermost five: the former revolves in the space of ten hours, and the latter in twenty-one and a half.

When the two Martian moons, Phobos and Deimos, were eventually found, by Asaph Hall at the US Naval Observatory, their orbits proved to be quite similar to those described in Swift's novel. Phobos is actually 6,000 km from the surface of Mars and revolves around Mars in 7.7 hours, whereas Swift gave the values 13,600 km and 10 hours, respectively. Deimos averages 20,100 km from Mars and orbits in 30.3 hours; Swift gives 27,200 km and 21.5 hours, respectively.

The two moons of Mars are Phobos and Deimos. Both moons were discovered in 1877 by Asaph Hall and are named after the characters Phobos (panic/fear) and Deimos (terror/dread). In Greek mythology they accompanied their father Ares, god of war, into battle.