Let's play What Is It?!

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Did you guess a Surveyor's chain?  In the early 1800's when

surveying tools were rare and primitive, a 66 foot long chain

composed of 100 links was often used to lay out towns.

Many city main streets were originally 66 feet wide, i.e., one length

of the entire chain.  Farms were also measured with these types of

gadgets.  Chains multiplied by chains equals acres with no more

calculations necessary: an area 10 chains by 10 chains equals 10 acres.

I've never seen one of these or if I did, I didn't

know what it was.  Now I'll keep my eyes open!