This is a surveyor's chain or Gunter's chain, an instrument used for measuring length. It comprises 100 pieces of straight metal wire, looped together end to end, and fitted with swivel handles. Its overall length is one chain (22 yards or 66 feet).
The Gunter's chain was named after its inventor, Edmund Gunter (1581-1626), an English clergyman, mathematician, and astronomer.
In the 16th century the mile was redefined and divided into eight furlongs, each of 625 feet. Following this an Act of Parliament in 1593 introduced a shorter English foot so that the furlong, divided into 4 rods, became 660 feet. The mile measurement consequently gained 280 feet and became 5,280 feet.
Measuring distance was problematic but into this mayhem came Edmund Gunter who in 1620 divided a furlong into 10 equal parts which he called chains. An area of one chain by one chain was one hundredth of an acre, while a square with 10 chains each side made up one acre. So it can be said that Gunter was a "metric visionary". To undertake ease of measurements, Gunter made an actual chain of 100 links that surveyors could easily carry to measure and survey ground accurately for both legal and commercial purposes.
This Gunter's chain, of 100 links (22 yards or 66 feet), features handles at each end with tally marks every ten links. These assisted the chain man to quickly count the number of links. It was made in England by James Chesterman & Co, of the Bow Works, Sheffield, which had been established in 1829. The chain was used in Australia for all types of land survey work and to peg railway centre lines. The Gunter's chain was eventually superseded by the steel tape measure.
Engineer's chains were used in the construction of works and differed from surveyor's chains in that they were 100 feet in length with each link being one foot long.
Dyson, James and Robert Uhlig (edits), "Mammoth Book of Great Inventions", Robinson, London, 2004, p.154.
Margaret Simpson, Curator,