These are simple catches, in which the sense is playfully cheated, and are generally founded upon words capable of double meaning. The following are examples:
Where did Charles the First's executioner dine, and what did he
He took a chop at the King's Head.

When is a plant to be dreaded more than a mad dog? 
When it's madder.

What is majesty stripped of its externals? 
It is a jest
[The m  and the y, externals, are taken away.]

Why is hot bread like a caterpillar? 
Because it's the grub that makes the butter fly.

Why did the accession of Victoria throw a greater damp over England than the death of King William? 
Because the King was missed  (mist) while the Queen was

Why should a gouty man make his will? 
To have his legatees  (leg at ease).

Why are bankrupts more to be pitied than idiots? 
Because bankrupts are broken, while idiots are only cracked.

Why is the treadmill like a true convert? 
Because it's turning is the result of conviction.

When may a nobleman's property be said to be all feathers? 
When his estates are all entails  (hen-tails).

Every Man Knows Where His Own Shoe Pinches.