This weeks fun phrase is ” Rule of thumb”
Meaning: A rough measure or guild.
History: The part of the thumb from the knuckle to the end is approximately one inch and has often served as a measure when a more precise one was not at hand. Probably the “rule” originated here. Sir William Hope told his readers in The Complete Fencing-Master (1692): ” What he doth, he doth by rule of thumb, and not by art.”