The units of measure in old deeds are not really confusing if you convert them into current terms. For example, a chain is the length of a cricket pitch. The original measurement was called Gunter's chain or a surveyor's chain and is 22 yards or 66 feet. The whole of the United States was measured and mapped using the Gunters Chain and his chain still applies to all title plans in use today. For this reason all city blocks, roads and avenues are multiples of the chain. Towns were laid out at 6 miles square or 36 sq miles. Early farms were sold to would-be farmers as lots of 640 acres or 1 sq mile. Imperial Measures of Length. A chain was made up of 100 links, each 7.92 inches in length. These measurements were standardized in 1607 by Edmund Gunter in England.
A chain was also equal to 4 poles. Each pole was equal to 5.5 yards. One rod was the same as a pole (and also the same as a perch). Therefore a rod is 16.5 feet.
There was another type of chain, called the Ramsden chain or engineer's chain, which was equal to 100 feet. There are a number of Websites that will automatically convert any unit of measure to another. See Unitconversion.org for example.
The Manual of Instructions for the Survey of the Public Lands of the United States; 1973
Prepared by the Bureau of Land Management, Technical Bulletin 6; pub. U.S. Dept of Interior states as follows:
- 1 yard = 3 ft = 0.9144 meter
- 1 rod, perch, or pole = 25 links = 16.5 ft
- 4 rods = 1 chain
- 1 chain = 4 rods = 66 ft = 100 links
- 10 chains = 1 furlong
- 1 link = 1/100 of surveyor's chain = 7.92 inches
- 25 links = 1 rod = 16.5 ft
- 100 links = 1 chain = 66 ft
- 1 furlong = 10 chains = 1/8 mile = 220 yards = 660 ft = 201.168 meters
- 8 furlongs = 1 mile
- 1 mile = 80 chains = 320 rods = 1,760 yards = 5,280 ft = 1,609.344 meters
- league = 3 statute miles = 4,828.032 meters