W. & L. E. Gurley began offering vara chains in 1874, noting that the Spanish or Mexican vara "is in very general use in Texas, Mexico, Cuba, and South America." This chain has 100 links made of No. 12 steel wire, brass handles and tallies, and measures 20 varas overall. The links and rings are brazed shut. The vara is roughly equivalent to 33 inches, but was never standardized as were the yard and the meter.
Ref: W. & L. E. Gurley, Manual of the Principal Instrument Used in American Engineering and Surveying (Troy, N.Y., 1874), p. 44.