Ward off Deer
Introduction
The shishi-odoshi (鹿威し), literally deer scarer, is a device that uses falling water to produce an intermittent sound. The bamboo-tube version is properly called a sōzu (添水). A length of bamboo is cut at an angle, pivoted off centre and fed by a small stream. Water collects in the open end until the tube becomes top-heavy, tips forward, empties, swings back and strikes a stone with a hollow knock.
The device was agricultural before it was ornamental. The sound startled deer and wild boar away from crops in fields nobody could watch continuously. It later entered garden design, where the best known example is at Shisen-dō in Kyoto.
A clock with no mechanism
The interval between knocks is set by two things: the volume of the tube and the rate of flow. Neither is adjusted by a control. Changing the interval means changing the water, which means that the device reports the state of the stream. A fast knock means the stream is running high. A slow one means it is low. A silent one means it has stopped.
The sound has properties that make it easy to live beside. It is short, it is broadband, it is irregular enough not to become a metronome, and it arrives at intervals long enough that the ear never habituates completely.
A sōzu does not need to:
- Be powered
- Be wound, set or calibrated
- Be reset after it fires
- Be monitored to know it is working
It is a timekeeper, a stream gauge and an animal deterrent built from one piece of bamboo and one stone, and each function is a side effect of the same physical arrangement.
Just as a bamboo tube marks time by emptying itself, a well-made device can carry several kinds of information through a single motion.
