Foot (ft): The foot is equal to 12 inches or 0.3048 meters. It is commonly used in everyday measurements, particularly in countries that do not use the metric system.
The term "long reed" does not refer to a standard unit of measurement or a widely recognized term in contemporary systems of measurement. It's possible that "long reed" is used in a specific context or industry, but it does not have a standard definition in general measurements.
If you have more context or specific information about how "long reed" is used, I would be happy to try to provide a more precise explanation.