Overview
The link, often called Gunter’s link, is a historic unit of length that formed part of Gunter’s chain system used in surveying. One link is one hundredth of a Gunter’s chain, a simple physical measuring device introduced in the early 17th century to make land measurement and area calculation straightforward. The link was widely used in the imperial and US customary systems for plotting and recording property boundaries before metrication and modern surveying instruments became standard. See the basic definition at Gunter's link reference.
Size and relationships
By convention a Gunter’s chain is 66 feet long and contains 100 links, so each link measures 0.66 feet (7.92 inches) or approximately 0.201168 metres. This simple fractional relationship made arithmetic easier for surveyors: 100 links = 1 chain, 10 square chains = 1 acre, and 80 chains = 1 mile. These interconnections meant land areas could be computed by counting chains and links directly in the field without complex conversion tables.
Construction and practical use
The link as a measuring concept was embodied in a physical chain composed of 100 small links. The device was low-technology, portable, and suited to measuring small plots, hedgerows and property lines with reasonable accuracy. Because the chain divided neatly into decimal-like subunits, it simplified calculation of acres and other traditional land measures. Surveyors commonly encountered links when reading older deeds and field notes; many historical land descriptions record distances in chains and links. For more on historical measurement practice see land surveying sources.
History and inventor
The chain and link are attributed to Edmund Gunter, a 17th‑century English mathematician and astronomer. Gunter devised the chain to standardize field measurement and to reduce arithmetic work in converting lengths into areas. His tools and tables influenced English and colonial surveying for centuries. Biographical or archival materials about him may be found at Edmund Gunter.
Legacy and distinctions
Although the link is now effectively obsolete for modern surveying, it survives in historical documents, cadastral records and some legal descriptions of land. Abbreviations and notations used in older records sometimes list distances in links, often abbreviated as ln. Modern readers and professionals who work with archival deeds need to understand conversions between links, chains, rods (poles or perches), feet and acres when interpreting those records.
Quick reference
- 1 chain = 100 links
- 1 link ≈ 7.92 inches ≈ 0.201168 metres
- 10 square chains = 1 acre
- 80 chains = 1 mile