Author:  Dr. Bob Wright, 2001

When someone asks "How tall is this horse?", the answer usually comes in units known as the "hand." It is a common unit of measurement now used only for quantifying the height of the horse.

Tracing a tradition backward is a dicey proposition. We know that today a "hand" is 4 inches, with one inch increments, and the measurement is from level ground to the highest non-variable skeletal structure on the horse, the withers.

History suggests that at one time, perhaps 5,000 years ago, it was as rudimentary as stacking a man's clenched fist one upon another, which tells us it was rather rough and inaccurate.

At some point, horse owners, and especially traders, agreed that the "hand" will always represent 4 inches, and will always measure the height from level ground to the withers.

But why a "hand"? In the ancient Mediterranean cultures, the hand unit developed – along with other measures – based upon references people of the time could relate to, such as body parts (e.g., foot). The problem was, whose foot, or whose hand? There were some inaccuracies.

Ancient Egypt - 3,000 BC
According to encyclopaedic sources, the "hand" measurement was four fingers wide at one point in time, and at others it was four fingers and a thumb wide. The rules of trade demanded the same measurement everywhere, and the hand was eventually standardized by the Egyptians around 3,000 BC based upon a complex system including the "cubit." Because of the enormous influence of the Egyptian culture, use of this system migrated to other countries and cultures.

The Cubit
In the Egyptian system, measurement was based on the cubit (sometimes mentioned in reference to the construction of the pyramids or Noah's ark). The Egyptian cubit is generally recognized as having been the most widely accepted standard of linear measurement in the very ancient world.

The cubit was based on the length of the arm from the elbow to the extended fingertips, an arbitrary distinction, which was then standardized by a royal master cubit of black granite. It was kept in a royal vault and all the cubit sticks in use in Egypt were measured at regular intervals.

This was not a planned system. It evolved, growing out of custom and popular usage, unlike planned systems of measurement like the Metric or the International System of Units (ISU) that we are more familiar with today.

The standardized "hand" has become as good an increment to use in the determination of a horse's height at the withers as any other. But it is by no means the only means.

Regardless of its origin, the hand has become a tradition of British measurement. In the rest of Europe however, height was – and still is – measured in metres and centimetres. In some places, like Europe and South Africa, there exists the dual situation of measurement in hands and centimetres.

1.  Where did the hand measurement originate from?
a.  Egypt               b.  Sumeria              c.  Greece                 d.  Japan

2.  The horse’s withers is equivalent to what part of a human’s body?
a.  top of head                 b.  shoulders                  c.  hips                 d. tailbone

3.  Most early measurements were based on what?
a.  a base 10 system                b. references to the body (hand or foot)
c.  sizes of animals                 d.  biblical references

4.  Why are these types of measurements inaccurate?
a.   the written language was not developed                   b.  horses were smaller
c.   humans come in different sizes                 d.  traders would lie about sizes

5.  How long is a cubit?
a.  four fingers       b.  one complete step    c.  waist to shoulders    d.  elbow to fingers

6.  If you were to measure your leg in hands, which measurement would most likely fit? 
a.  3-5                    b.  12-20                                c.  30-50                     d. 80-100

7..  What other measurement is commonly used in English-speaking an country that is based on a body part?    
a.  cubit            b.  pace     c.  centimeter             d. foot

8.  Measurements that are “standard” do not:  a.  compute   b.  vary   c. travel  d.  flow

9. What is the purpose of having standard units?

10.  The United States and England are two countries that still use the English system, using feet and inches for measurement of lengths. Other countries use meters and centimeters.  What problems might this cause during science communication?