Parts of the body have long been used to define small distances – the foot in the imperial system of measuring, for example. The Zarma people of Western Africa find the arm much more useful: kambe karis the length of the arm from the elbow to the tip of the middle finger and gande is the distance between two outstretched arms. Elsewhere we find:
• dos (Hmong, China) from the thumb tip to the middle-finger tip
• muku (Hawaiian) from the fingers of one hand to the elbow of the opposite arm when it is extended
• sejengkal (Malay) the span between the tips of the stretched thumb and little finger
• dangkal (Kapampangan, Philippines) between thumb and forefinger
Oddly enough, the word fathom also has an interesting lineage. If you stretch out your arms to either side of your body as far as they’ll go, the distance between the tips of your middle fingers will be very close to your height, or about six feet—your own feet, that is— measuring a fathom.