Limericks are five-line poetry having an AABBA rhyme scheme. It is formally classified as a 'anapestic trimeter.' The 'anapest' is a literary poem foot of three syllables, the third lengthier (or more emphasized) than the first two: da-da-DA. The term "limerick" comes from the Irish language for "three songs," because these poems consist of three stanzas that usually include one central theme. The first recorded example of a written-down limerick was published in London in 1771. They became popular among poets in late 18th-century England, when political cartoons were lacking due to the passing of the Stamp Act. The form began as a parody, with obscene subject matter and random lines being added together to make a humorous whole. Modern-day examples include John Bunyan's The Limberlost Songbook and William Shakespeare's The Merry Wives of Windsor. In America, limericks were popular among artists and writers during the 19th century. For example, Washington Irving included several limericks in his book Tales of a Traveller. H. L. Mencken referred to himself as the "limerick king" after writing dozens of them. Robert Frost also wrote numerous limericks, some of which appear in A Boy's Will. Charles Darwin collected many limericks in his book Limericks of the West Country. One of the best-known modern examples is E. B.