Surveying and 400 degree circles.

[ttw]

Units never go away. Old measurements in the US Southwest were in varas (33 and 1/3 inches or 33 inches or something larger for rich land owners.) Contracts were drawn up in these units and are guaranteed for Spanish Land Grant holders by the Treaty of Guadalupe Hidalgo. A change to metric will still leave varas, inches, feet, USGS Feet, etc., and add meters, metres, kilos, etc.