Why did the jury bring rulers to deliberation?

The humor in the joke about the jury bringing rulers to deliberation stems from a delightful bit of wordplay. It cleverly plays on the double meaning of the phrase "to measure the evidence." In a legal context, when a jury "measures" evidence, they are figuratively assessing its weight, credibility, and significance. They carefully consider all the facts and testimony presented to them to reach a verdict.

The punchline, however, takes this figurative expression and twists it into a literal, physical act. The mental image of a group of jurors meticulously pulling out actual rulers, tape measures, or protractors to physically gauge a witness statement or a piece of forensic evidence is inherently absurd. This unexpected shift from the abstract, intellectual process of evaluating evidence to a concrete, impractical action is what creates the comedic effect.

In a real courtroom, jurors are tasked with critically evaluating the information presented, weighing arguments, and applying the law to the facts, all without the need for physical measuring tools. The joke playfully subverts this serious judicial process by taking a common idiom literally, providing a lighthearted moment that highlights the sometimes-stuffy language of the law.