Incense Clocks: To Measure Time, Set the Timepiece on Fire

When your clock is made of incense, time doesn’t just pass - it smolders away, fragrant and fabulous.

Forget the sterile tick-tock of quartz: in old Japan, time-telling could be done with something that left the room smelling divine.

Japan Meets Incense: A Love Story in Fire and Smoke

Incense spread to Japan along with Buddhism and has perfumed its rituals since at least the sixth century.

But one of the earliest instances of Japanese incense appreciation began as a cooking accident. The Nihon Shoki chronicle notes that, in AD 595, a massive piece of aloeswood drifted ashore on Awaji Island, where the unsuspecting locals threw it on a cookfire.

Cue heavenly aroma, cue confusion, cue mysterious wood being presented to the reigning empress.

More than a century later, another gift of precious wood - from the Chinese court to the Japanese emperor - was made. Named Ranjatai, it's preserved in the Shosoin treasure repository of the Todai-ji temple complex.

Ranjatai today measures about 1.56m in length and 11.6kg in weight: somewhat diminished because, over the centuries, emperors, shoguns and warlords have helped themselves to bits.

Ashikaga Yoshimasa, the Gen Z shogun more into aesthetics than governance, took some, as did warlord and tea ceremony disruptor Oda Nobunaga. Even Emperor Meiji, surrounded by the novelties brought by Westernization, couldn’t resist a cut.

The fragrant prize in both cases was jinko, Japan’s word for aloeswood, also known as agarwood. This was no ordinary wood: jinko refers to the resin-rich heartwood of Aquilaria trees native to South-east Asia.

Normally, the tree’s wood is pale and light but, when wounded or infected by fungus, the tree responds by producing a rich, dark resin as a defense. That resin transforms the heartwood into a dense wood heavier than water. The Chinese call it 沈香 ('sinking aromatic') - 'chen xiang' in Mandarin and 'jinko' in Japanese.

Only about 7% of wild Aquilaria trees produce agarwood, and even then the quality varies, making the finest grade literally worth more than its weight in gold.

Rare and absurdly expensive, agarwood nonetheless became the backbone of Japanese incense, blended with materials such as sandalwood, cinnamon and fragrances derived from seashells.

The Trail of Incense in East Asia

With the burning of aromatics for secular and religious use came the whiff of another idea: using fragrances to measure time.

The incense clock had smoldered into existence in China by at least the Tang dynasty. This wasn’t incense burning for pleasure or rituals; it was using incense as a piece of technology.

The Chinese incense clock measured time by burning powdered incense along a pre-measured path - essentially, a slow, fragrant fuse.

It worked as a clock because of its steady, constant combustion. If shielded from drafts, a stick or powdered trail would burn at a predictable rate, making it more accurate than water clocks, which also had the unfortunate tendency to freeze in winter.

Incense timepieces were more reliable than other clocks used in ancient times. Unlike sundials, they worked rain or shine and you could use them indoors. Burning with a steady ember rather than an open flame, they posed far less of a fire hazard than candle clocks did.

And, unlike roosters, incense never overslept.

Don't Know What Time It Is? Ask a Cat

While the Japanese imported Chinese methods of time measurement, they do not seem to have adopted use of the cat.

In The Trail of Time, historian Silvio Bedini describes how a feline might become a timepiece, recounting the experience of a 19th-century French missionary in rural China who asked a farm boy if noon had arrived.

The boy left his work and returned with a cat in his arms. No, he said, 'it was not yet noon; one could tell from the cat's eyes'.

The missionary later found out that it was common among the rural Chinese to tell the time by checking a cat's eyes. They had learned that the pupil of a cat's eye narrowed as the light increased: 'By noon, the pupil was reduced to a very thin line, and then the pupil gradually dilated and became larger and larger as the afternoon advanced.'

Delightful as cat chronometers may sound, they come with obvious flaws. A clock that keeps wandering into the neighbor's garden is hardly reliable - and humanity, for all its ingenuity, has yet to find a way to strap a cat to the wrist.

Set the Clock with the Scent of Time

In Japan, incense was used to measure time from the 8th century, if not before. The Japanese adopted the techniques from the Chinese but developed them into devices that were distinctly their own.

Categorized as koban-dokei (香盤時計), these timekeepers included both the jikoban (時香盤) used in temples and the jokoban (常香盤) that supported community and civil life.

At its simplest, an incense clock consisted of a square wooden box filled with a bed of finely sifted wood ash. Into this ash, a trail of incense powder was impressed using a stencil or wooden mold.

The trail was often a continuous furrow of powdered incense, sometimes straight, sometimes arranged in intricate shapes such as swastikas or zigzags. Once formed, the furrows were tamped flat with a little shovel, ensuring even burning.

Small wooden or metal plates, engraved with characters or symbols, were sometimes inserted along the trail to calibrate intervals of time. Some clocks were designed to burn for a few hours; others could mark an entire day.

Role in Buddhist Temples and Civil Life

In temples, incense clocks were used to regulate the hours of prayer, meditation and rituals.

In civil life, kobandokei had far wider applications. They were employed at the Imperial Court, in noble residences and in government offices.

Official timekeeping in cities such as Kyoto was often coordinated with the burning of incense trails, supplemented by drums or bells to inform the public of the time. Regulations for express couriers, marketplace hours and even judicial proceedings were tied to time divisions established by incense clocks.

In short, the clocks were used not only to regulate religious life but also to structure the civic order of society.

Water Driven by Fire Clocks

Incense clocks weren’t only for monks and courtiers; down in the paddies, farmers relied on them too.

The problem was irrigation. Rice paddies needed water but every family wanted more than was available. The solution? Allot each household a slice of time, measured with incense.

This practice, devised as a means to control water rights, was so widespread that it became embedded in local law, complete with its own terminology: a kosun - incense inch - meant the length of time required for powdered incense to burn along a groove of the incense tray.

When the ember finished its appointed crawl, the water gate was closed for one family and opened for the next. Elders oversaw the process, striking a bell when the incense had burned to the proper length.

Of course, irrigation duty could get dull, so the bottom tray of the jokoban was used to store game boards and pieces. Elders on incense-watch would while away the hours with checkers or chess, this being long before Candy Crush was an option.

Burning Time – and Money

Faraway from rice paddies as the geisha world might seem, there too, aromatics were used to measure time.

There were no ticking clocks in the houses where geisha entertained but there were sticks of incense - charges were calculated not in hours but in the number of sticks consumed.

The system was practical yet elegant. Each guest’s time was marked by dropping a fresh stick into a wooden or bamboo holder bearing the geisha's name inside a box called a senkodokei, or incense stick clock.

One stick took about half an hour to burn down, with the time spent with one customer in one evening averaging at the equivalent of four sticks.

When the incense had burned down, the charred remnants were collected and set aside with the geisha's name - physical receipts in ash. Even as late as 1924, geisha entertainment accounts were still calculated in this way.

At the end of the night, the mistress of the house would tally up the evening’s entertainment. Guests, in other words, could drift into the illusion of timeless pleasure, but the house always knew exactly how much time had been spent.

Listening to Fragrance

The Japanese didn’t stop at the use of fire and incense for time measurement. They transformed it into kodo (香道) - the Way of Incense - which may sound like a martial art but has more to do with inhaling with gravitas.

If incense clocks measured time, kodo measured presence. Practitioners like to say they listen to incense, not smell it.

Aristocrats held contests to guess the blend or origin of fragrant woods, creating a poetic maze of incense. Samurai sharpened their senses at incense gatherings because nothing says 'battle-ready' like being able to distinguish Cambodian agarwood from Vietnamese.

The pastime spread to the wider population and as it grew, so did the rules and manners governing the practice.

At a formal kodo gathering, ritual and etiquette reign. Knowledge of different types of incense is important but familiarity with Japanese literature is also vital.

Leave it to Japan to take fungus-infected wood and turn it into high culture.

Stop and Smell the Incense

With the popularization of mechanical clocks, incense gradually shed its timekeeping duties.

Today, it’s your personal pause button. Specialty shops in Kyoto and Tokyo sell sticks, cones and coils promising relaxation, focus or spiritual clarity.

Even if you never take part in a kodo gathering, you can still carve out incense time. Light a stick and sip some tea: it’s not about measuring hours for irrigation or billing - you're measuring out a pause for yourself.

Not only does this pause smell better than coffee, it also does a better job of telling you to be present than your phone notifications ever will.

Whether by clock or by curl of smoke, incense reminds us that the present is already here - and it smells wonderful.

By Janice Tay