Archaic units of measurement

[watervole]

Ever wondered where these funny old units of measurement come from?  They were originally very practical units of measurement.

eg. Allotments are typically 5 or 10 rods in length. (a pole is the same measurement as a rod)

Plot sizes are measured in rods, an old Anglo-Saxon unit so-called because it was the length of the rod used to control a team of eight oxen (thus an item of standard length that was likely to be around and handy for measuring stuff).

A rod is 5.5 yards (5.03 metres).


An acre is the area of land that could be ploughed in a day, being a furrow long (one 'furlong')and a chain wide.

Turning a team of oxen was difficult, so the typical acre on the ground was a long narrow shape.  Short furrows would drain better, but long ones were easier to plough. The furlong was a compromise between the two factors.

A furlong = 10 chains.

But the chain has an extra layer of meaning.  It was the measuring tool of surveyors and had to be strong enough to not stretch, but light enough so that the surveyor could still carry it.  It was literally a chain, typically made with 100 links.


A chain = 4 rods = 22yd (20.12m) and is the length of a cricket wicket.  (I guess the surveyor's chain was another handy item)

A mile is 8 furlongs or 80 chains.

A foot is pretty self-evident.

An inch is derived from the width of a man's thumb at the broadest point. Again, one can see this as an easy practical measurement.

A fathom is used mainly at sea for measuring depth.  6 ft, fingertip to fingertip of outstretched arms.  Think of how you quickly measure the length of a rope and you can see why depth measurements made by a man dropping a lead on the end of a piece of thin rope would obviously be measured in fathoms.

 

A mile = 8 furlongs.

An acre is the area of land that could be ploughed in a day, being a furrow long (furlong)and a chain wide, or 160 square rods.