So, how do you write one? Well, the first thing you need to know is that these poems are biographical, focusing on a specific detail of a well-known person so as to poke gentle fun at them. There are four lines of no set length, although the first two are usually short and the second two long. The first line is usually wholly or partly made up of the subject's name. These lines rhyme AABB, with portmanteau words and other linguistic innovations encouraged to achieve the rhymes. Although the results are (or at least meant to be) funny, Clerihews are rarely satirical and never abusive. Behind the wit, you can generally sense great admiration for the subject. If anything, most Clerihews are best seen as ironic eulogies.
It was a weakness of Voltaire's
To forget to say his prayers,
And one which to his shame
He never overcame.
-- Edmund Clerihew Bentley
"Walter Bagehot, editor of the Economist from 1859 to 1877, advocated
`animated moderation' in writing. And Sir Walter Layton, Crowther's
immediate predecessor, spent hours rewriting his staff's articles--so many
hours that one of his frustrated colleagues hit back with a clerihew:
Sir Walter Layton
Has a passion for alteration
Would to God someone could alter
St. Thomas Aquinas
Tried to incline us
To read through his 'Summa';
I'm afraid it's a bummer.