Text by Yozo Nanba, Department of Archaeology
English translation by Melissa M. Rinne, Department of Archives
(Issued on February 12, 1994)
Do you know what archaeology is? Maybe it is easier to tell you what we archaeologists do. Archaeologists analyze remains and artifacts from the past. Then we try to piece together this information to understand the cultures and civilizations from which they came.
In order to do this, however, we have to figure out the chronological order in which the artifacts were made in history. For that reason, archaeologists spend a lot of time researching excavated objects, such as tools, trying to decide which came first and which came later. We then use these tools to make a sort of object "timeline."
Let's take a look at one of the ways archaeologists find the chronological order of various artifacts. This method involves finding something called a "rudiment," a vestige of the past that is no longer functional.
Just as animals gradually adapt to the environment in which they live, we humans are constantly updating and improving the tools and objects that we use in our daily lives. Even if such changes are very small, many changes over time often result in an end-product that is totally unlike the original! Archaeologists study these changes in great detail in order to decide the chronological order of the artifacts.
Let's take a look at the shape of Japanese public telephones as an example of how modern objects have changed over time.
(1) is the oldest of the four models. This phone has a receiver resting on top and a big dial in the center, reminiscent of old-fashioned, desktop dial phones.
(2) has a smaller dial and a receiver hanging on the side of the phone. The coin slots have been moved to a protruding section on top of the phone.
In (3), the dial has changed to push buttons. Though the buttons are arranged in a square, they are placed on top of a round pad, which doesn't seem to fit. This is probably because the design was based on the model of type (2), which still had a round dial.
Type (4) has removed the meaningless, round pad all together and the coin slot has been placed in the main body of the phone. The phone-card slot is a new addition.
Most of us living in Japan have seen with our own eyes these changes occurring over time, so it is easy for us to understand that the models were made in an (1), (2), (3), (4) order. If we had no prior knowledge, however, we might decide that having a dial and a receiver on top was the more advanced model. In that case, the opposite progression, (4), (3), (2), (1), from a push-button card phone to a dial phone would seem logical.
If you think carefully, however, you will realize that (3), square push-buttons on a round pad, would never have been made but for the influence of a round dial (2) before it. Thus a (3), (2) progression is impossible. If a (3), (2) progression is impossible, then the proper order must have been from (1)-(4).
The important point here was that the round pad under the square push-buttons were a meaningless vestige left over from the former, dial-phone model. Human beings have a meaningless vestige too: we still have tailbones, though we don't have tails! Such vestiges of the past which no longer have a function are called rudiments. You can see from this public telephone example how important it is to detect rudiments in order to determine the chronological order of artifacts, from any time in history.
Now that you have seen one example of how to date objects, see if you can figure out the following problem on your own. The following are three bronze spearheads from the Yayoi period (200 B.C.- 250 A.D.). The black horizontal lines are cross-sections at each point.
Answer: The spearhead on the left is the oldest and most functional of the three.
The spearhead on the right is the newest and most ceremonial.