Suikinkutsu (a traditional Japanese echoing system in the garden, like a water harp) (水琴窟)

Suikinkutsu is a decoration device in a Japanese garden that generates a sound like the koto (Japanese harp) with drops of water.

About structure, it is an inverted jar with a tiny hole in the bottom buried in the soil and the bottom is fixed with clay such that it collects some water. A wash basin (Chozu-bachi) is generally set above, and water drips from there and drops through the hole of the jar. The sound at that time echoes in the bottle and sounds like a harp. A traditional Suikinkutsu is often built in the Tsukubai (stone wash basin found in Japanese gardens) in front of the tea-ceremony house.

Traditional construction method
In order for the Suikinkutsu to emit a good sound, adjustment is necessary for the combination of each element, such as the jar.

The most important thing is for an inverted jar put into the soil. While in recent years, there have been also metal jars, it is assumed that the most suitable jars are unglazed earthenware for storing rice grain or water. The depth is from 30cm to 1m, the diameter is from 30cm to about 50cm, and the hole in the bottom is assumed to be about 2cm. If there is a crack in the jar, it may not result in a good sound.

The jar is turned up-side down and fixed onto the ground with clay (or mortar in recent years) to prevent water from leaking into the hole that was dug up. The old suikinkutsu adopts a method whereby the water is takes time to flow out naturally, however, because it does not keep a constant tone, a draining tube is installed to keep the water level constant. The surroundings and the upper part of the jar are completely covered with small stones, and a wash basin is placed on top. Sometimes, a bamboo shaft is installed so the sound can be heard.

The elements and structure have variations, depending on the region and the era. Usually, there is only one jar but sometimes there are two: examples include Iwasaki-jo koen (Iwasaki Site of a Castle Park) in Nisshin City, and University of Creation; Art, Music & Social Work, in Takasaki City of Gunma Prefecture.

Nowadays, there are various designs.

Nowadays, people do not hold on to tradition and they try to create variations of suikinkutsu. For instance, the following examples exist.

There is no wash basin, suikinkutsu is not in this Japanese garden.

The set up is such that the water flows continuously without any interruptions.

Instead of earthenware, a metal jar is used.

Instead of the ground, it is set up on a part of a sculpture, etc.

Indoor installation.

In order for the sound to be easily heard, it is amplified electronically and broadcasted through speaker.

The monument called 'The Phoenix water clock' of Kyoto Station Building is an example having all of the above-mentioned variations. Instead of being a suikinkutsu with a wash basin in a Japanese garden, it is a suikinkutsu with a glass clock of water emitting a continuous amplified sound decorated by a sculpture (to be more precise, it is a comic book character) built inside the waiting room of the station building.

History
It seems that suikinkutsu was first called Tosuimon (a drain facility of the lavatory) that was not built in a garden, but was a facility for drainage of a lavatory basin when washing hands. Noticing that it sometimes gave a good sound, a gardener improved the device. It became known as suikinkutsu during the mid Edo period. It is said that it was invented by a famous contemporary master of tea ceremony Enshu KOBORI, who was also a garden designer. In the late Edo period, it was once abolished, although it was revived during the Meiji period, and in the early Showa period it was almost forgotten. In a report by professor Hirayama's of Tokyo University of Agriculture in 1959, there were two examples cited, but most were buried in the ground and this was a difficult situation for restoration. However, an article in 1982 appeared in the Asahi Shinbun Newspaper that led to the rediscovery of a lot of different types of suikinkutsu. The following report produced by Japan Broadcasting Corporation, later brought about public attention again. As a garden ornament that emits sound, there was also the shishiodoshi (decorative bamboo irrigation pumps). Comparatively speaking, because a suikinkutsu has smaller volume and better sound quality, it was quite commonly installed in private houses.
Sound

The sound of Suikinkutsu is called suikinon.

The sound can be further classified into two types; namely a water flowing sound and a water dropping sound. When one washes one's hands, the majority of water goes along on the edge of small stones or the jar, it flows, and then leaves; this is the water flowing sound, in harmony with the water dropping sound inside. When one finishes washing one's hands, the water flowing sound gradually fades out and only the water drops can be heard.

A well designed suikinkutsu has water dripping and dropping from multiple positions of the jar. A good unglazed pottery jar has water dripping and dropping from multiple inside positions where moisture is often maintained. The sound is generated when the water drop falls onto the water surface and echoes inside the jar and is amplified. The sound quality changes in response to various conditions such as the shape and size of the jar, and the moisture condition at the bottom.

Although suikinkutsu can be found in various places, it is said that no two suikinkutsu give the same sound.