Clause 35 of the Magna Carta defines some standard weights and measures to be used throughout the realm. The first part is straightforward: the standard weight/mass used for wine, ale and corn is the London quarter. But I don't understand the second half about the lengths to use for cloth.
Here are two English translations I've found:
Let there be one measure of wine throughout our whole realm; and one measure of ale; and one measure of corn, to wit, "the London quarter;" and one width of cloth (whether dyed, or russet, or "halberget"), to wit, two ells within the selvages; of weights also let it be as of measures.
There shall be standard measures of wine, ale, and corn (the London quarter), throughout the kingdom. There shall also be a standard width of dyed cloth, russett, and haberject, namely two ells within the selvedges. Weights are to be standardised similarly.
What does "two ells within the selvedges" mean? What's an ell? What's a selvedge?