Convert from finger to chain [Ramsden, engineer]

Unit Definition (finger)
The finger is a traditional unit of distance equal to 2 nails or 4.5 inches (11.43 centimeters). This unit represents the length of the middle finger, from the tip to the joint where the finger is attached to the hand.

Unit Definition (chain [Ramsden, engineer])
The Ramsden chain is quite different to the Gunter chain. The Ramsden chain was commonly used by American surveyors. It equals approximately 100 feet and is also known as the engineer's chain.