A "finger" is a traditional unit of length used for measuring cloth or fabric. Similar to the span, the finger is based on the width of a human finger. It was historically used in various countries, including England.
In England, a finger was typically equal to about 2.25 inches or approximately 5.715 centimeters. However, like other traditional units of measurement, the precise length of a finger could vary depending on the region and historical context.
A "ken" is not a widely recognized unit of measurement in modern systems. However, the term "ken" is more commonly used as a noun or verb in English and has a different meaning.
As a noun, "ken" refers to one's range of sight, perception, or understanding. For example, you might say, "Beyond my ken," to mean something is beyond your understanding or knowledge.
As a verb, "ken" means to understand, perceive, or know. For instance, you might use it in a sentence like, "I cannot ken the complexity of this issue."
In these contexts, "ken" is used to describe one's ability to perceive or comprehend something, rather than a unit of measurement. If you have a specific context in which "ken" is being used as a unit of measurement, please provide more details, and I'll do my best to assist you further.