Convert from barn to labor

Unit Definition (barn)
The Barn is a slightly humorous unit of area used in nuclear physics. When atoms are bombarded with smaller particles such as electrons, the electrons are scattered as if the nucleus of the atom was a tiny solid object. The barn is used to express the apparent cross-sectional area of this scattering object. One barn is equal to 1E-28 square meters. Using this unit, physicists can say that such and such a nucleus is "as big as a barn", or 10 barns, or whatever. The proper SI unit to use for these measurements is the square femtometer (fm²); one barn equals 100 fm².

Unit Definition (labor)
The labor is a traditional unit of area in Latin American countries. The labor is equal to the area of a square 1000 varas on a side, or 0.04 legua. Using the Texas standard for the vara (33 1/3 inches), this is equivalent to 177.136 acres or 71.685 hectares. The word labor means work in Spanish, as it does in English. As a unit it represents the area that could be cultivated by a single farmer, somewhat like the old English hide.