How big is a 'kan'?

By Kim Ji-myung

One big difficulty that researchers of Korean history face is the issue of units. Length, area, weight, volume and time seem to have been measured by a variety of standards, depending on periods and areas.

Old records tell us that most unit systems were made in ancient China and spread to Korea and other neighboring countries. In the case of “pyeong” to measure land and field space, it was exported to Japan during the Three Kingdoms period as a unit of 3.158 square meters as used in the ancient Korean kingdom of Goruryeo and Tang China. Later it was introduced back to Korea by Japan as 3.3058m² per unit as standardized in Japan in 1874.

The “ja” or “cheok” is a unit of length like a foot in the West. Just as with any unit system, the ja is divided into smaller units, in this case 10, called “chon.” Before the Goryeo period, roughly until the 10th Century, countries had different standard unit lengths which were recorded as Han Chinese unit, Tang unit or Goguryeo unit.

However during the Joseon period (1392-1910), different rulers were used with differing lengths for the same unit depending on the areas of work. For example, there were different lengths of the same one cheok for a traditional architecture unit and for a unit of fabric. By the way, cheok means both the unit length and the ruler.

Archaeological research for unearthed rulers has discovered differing unit sizes for different rulers by ancient countries. Many Joseon period rulers are displayed at museums. For example, a ruler was created by Pak Yeon during King Sejong's reign in the 14th Century to tune the key notes of musical instrument strings to those of China.

We can see rulers for building construction, for ritual vessel production and measuring fabric and clothes making, all displayed at museums.

The Joseon court understood the importance of unified units and they made a special kind of square stick brass ruler for nationwide standardization. Newly assigned rural magistrates and confidential investigators brought these brass rulers to check if there had been any alteration or falsification of measurement units. Being made square shape and of brass, the rulers functioned as a perfect standard.

The use of a unit dies hard. In 1960, Korea adopted a comprehensive modernized unit system to apply meters, cc, grams and square meters across the nation. But old measurements of “geun” for weight and pyeong for floor space seem to strongly persist.

How many foreigners would know that a geun of meat is 600 grams while a geun of fruit is 400 grams in Korea? Most aged housewives and merchants find no problem with that although it is different with younger generations.

For me, converting from pyeong to square meter to imagine the size of a room or a house is most difficult. Isn't it awkward to tell the floor space of a housing unit by 79.2 square meters or 108.9 square meter instead of 24 pyeong or 33 pyeong?

If the square meter is going to function as a unit of floor space in its true sense, and not just a nominal mark, we should say 80 square meters or 110 square meters for 24.24 pyeong or 33.33 pyeong, respectively. But housing sales ads continue to use m² as a nominal unit which appear in odd figures. In reality the planning and designing is done, as usual, based upon the traditional concept of pyeong sizes.

A most challenging issue concerning the traditional unit of measurement is “kan” problem. Did anyone tell you how large is one kan? Well, it is a basic length between two supporting pillars of a traditional structure.

Then how long is the distance between the two pillars? The ambiguity of this kan starts here. Joseon had rules on how many kans were allowed to different ranks of people in society. But still there was no definite figure about the length.

I heard the Japanese also used kan unit or the ken in Japanese extensively in traditional Japanese architecture such as in Buddhist temples and Shinto shrines.

This confusion over this kan appeared rather dramatically in the results of a recent comprehensive analysis of on-site interpretation texts for cultural heritage sites.

The word kan appeared 142 times with 22 different translations according to the survey of on-site interpretation texts on boards.

The reason is that there were so many explanations about the architecture. And most extant cultural heritage sites are Joseon period palaces, Buddhist temples and shrines, and Confucian school buildings.

Some of these terms are: bay, room, section, space, partition, distance between two beams, kan (one kan = about 1.82m), kan (a unit of area), kan (a kan is the space between two pillars), kan (a traditional architectural measurement, meaning the distance between two columns), kan (unit for the space enclosed by four pillars), and kan (unit of floor place).

These translations and annotations show the translators' efforts to offer an understandable explanation in English.

Is it impossible to make a rule to measure the existing heritage buildings by meters and square meters and just use them? Is kan the only unit or an absolute concept in understanding an Asian architecture? Maybe now is the time to review our approach to narrating our culture and history from scratch.

The writer is the chairwoman of the Korea Heritage Education Institute (K*Heritage). Her email address is Heritagekorea21@gmail.com.