The height of a horse is sometimes given in units of "hands". Why was this a poor standard of length before it was redefined to refer to exactly 4 in.?

And your thinking is...? I noticed my neighbor's hands, a small woman, are pretty little.

We will be happy to critique your thinking or work.

Before the unit "hand" was redefined to refer to exactly 4 inches, it was indeed a poor standard of length. The reason for this is that a "hand" was originally measured as the width of an average person's hand, which can vary significantly from person to person.

Using an inconsistent and subjective standard like the width of a person's hand can lead to inaccuracies and inconsistencies when measuring the height of horses. Different people might have different-sized hands, making it difficult to establish a consistent and reliable measurement system.

To overcome this issue, the unit "hand" was redefined to be a standardized length of exactly 4 inches. This redefinition created a consistent measurement that could be universally applied by measuring from the ground to the highest point of the horse's withers (the ridge between the shoulder blades). This standardized measurement ensures accuracy and comparability when discussing the height of horses.

Regarding your neighbor's hands being small, it is important to note that the unit "hand" in the context of measuring horses does not refer to the size of a specific person's hand. It is a standardized measurement that has nothing to do with an individual's hand size.