Puerto Rican units of measurement
System before metric system
Several units were used before metric adoption. These units were older Spanish units.
- Washburn, E.W. (1926). International Critical Tables of Numerical Data, Physics, Chemistry and Technology. 1. New York: McGraw-Hil Book Company, Inc. p. 10. Retrieved 8 February 2015.
- Units - Cuerda. Sizes.com. Puerto Rico Act 135, section 4 (page 100), 1913–14, as amended by Act No. 3, 1913–14: A cuerda, quote: "a unit of land area, approximately 3,930 square meters (approximately 0.971 acres)...In land measurements and records, the measurement by cuerda customarily used in Porto [sic] Rico...equivalent to 3,930.395625 square meters..."