Unlike the other two inventions Swift mentions, this actually exists. In 1714 the government offered a reward of £20 000 (about £2.5 million in today’s money) for anyone who could invent a way of working out longitude at sea. The problem was eventually cracked by John Harrison when he perfected his marine chronometer in 1759.

Swift seemed to think that the problem was impossible, as he ridicules it not only here but in the Memoirs of Martinus Scriblerus (co-written with Alexander Pope and John Arbuthnot, among others), where Scriblerus proposes building

Two Poles to the Meridian, with immense Light-houses on the top of them.

Ain’t dat neat? It only works if you spell ‘iust’ with an ‘i’, though.

“The tour” is an allusion to the early-18th century Tory leader Henry St John, who supposedly used the alias ’M. la Tour' during his exile in France.

#WRONG.

The original has the spelling “Langden”, which is an anagram of “England”. Which also makes more sense than Scott’s reading, as it’s more accurate to conflate Britain with England than with London.

The island of Laputa is Swift’s satire on scientific rationalism, or the belief that knowledge should be based on scientific deduction rather than on physical experience. The Laputans take this to laughable extremes: even physical beauty is talked about in terms of geometry. Music is placed alongside math in Swift’s satire: in the early eighteenth century romanticism hadn’t quite hit the market yet, and people mostly thought of music in terms of intervals and mathematical relations between notes.

Gulliver’s Travels has often been charged with misogyny: it’s worth noting that Swift says “a woman, or any other animal” here.

He was as merry as a goldfinch in a thicket

Goldfinches are brightly coloured and sing a cheerful song, but like the apprentice they don’t really achieve all that much while they’re singing.

“Whilom” means ‘once upon a time’. Chaucer’s cook is setting the scene: “our city” is London, and the main character of the tale is a grocer’s (“victuallers”) apprentice.

The practice of apprenticeship reached its peak in Chaucer’s time, and a lot of writers wrote about bad apprentices, either to condemn them in moral texts or – as Chaucer does here – to make a joke out of them.

“The King’s tune”. Nobody knows what tune Chaucer’s talking about, but I like to think it was a reference to the King of Rock and Roll:
http://www.youtube.com/watch?v=ViMF510wqWA

But to tell you about what he was wearing …

The General Prologue tells us what pretty much all of the different pilgrims were wearing. Chaucer’s characters are often reflected in the ways they present themselves, whether that’s in their clothes, or, when each pilgrim comes to telling her/his tale, in their language. Can’t help feeling that the great poet’s forgotten something:

You can find the first part of the Squire’s Tale here.