Convert from mark twain to township

Unit Definition (mark twain)
The mark twain or twain is an old word for the number two, derived from the Anglo-Saxon twegen. The American author Samuel Clemens (1835-1910), who had been a riverboat pilot on the Mississippi in his youth, took his literary name from a traditional riverboat phrase "mark twain", meaning "exactly two" fathoms of water. This was the minimum depth needed for the boats to operate safely without running aground.

Unit Definition (township)
A Township in the United States refers to a small geographic area, ranging in size from 6 to 54 square miles (15.6 km² to 140.4 km²), with 36 square miles (93 km²) being the norm.