চন্দননগরের আলোকসজ্জা

Chandannagar was a French possession on the west bank of the Hooghly from 1673 until it voted to join India in 1949, and its great festival is not Durga Puja but Jagaddhatri Puja, held a month later and said to have been introduced there by a local zamindar in the late eighteenth century. The illumination began as procession lighting. Before electricity reached the town, gas lamps were mounted on bamboo frames and carried with the goddess; when the supply arrived, the frames stayed and the lamps changed.

The person who turned that into an art form was Sridhar Das. He began as a schoolboy in the early 1950s, building his first display for a school Saraswati Puja out of barley tins and coloured cellophane, and he never studied past Class Eight; he learned electricity doing odd jobs at an electrician's shop. His father threw him out for giving up a mill job, and the family of his friend Bikash Ghosh kept him. In 1965 he made his first running lights for the Jagaddhatri Puja at Narua, using a flat wooden board and ten-foot arches. In 1968 he was hired by the Bidyalanka puja committee to write the word Bidyalanka in Bengali in 25-watt lamps strung on heavy wire and set underwater in a pond; the Boroline company commissioned the same trick for its brand name in 1969. During one demonstration a loose wire caught his finger and he was badly burnt on his hand and back. He was still recovering when he took the commission for the puja of the West Bengal chief minister Siddhartha Shankar Roy in 1970.

His mechanism was a wooden roller with copper contact strips — a rotating drum switch that closed circuits in sequence, animating an image made of thousands of bulbs. At the Festival of India in Moscow in 1985 he showed ten panels of twenty by twelve feet each; the Soviet organisers, assuming computer control, asked to keep a roller for a museum. He later worked in Ireland, in Los Angeles on an AIDS awareness display, and in London, where in 2003 he floated a seven-metre mayurpankhi, a peacock boat, down the Thames, carrying 130,000 tuni bulbs.

Chandannagar solved the problem of the moving image with a wooden roller and a lot of patience, and it did so in a small town on the Hooghly, decades before anything about it could be programmed. That is the whole point of the craft: a deer runs, a dancer turns, Durga's spear goes into Mahishasura, and the animation exists nowhere except in the timing of contacts closing on a rotating drum. It is folk engineering of a high order, and it was invented by people with no formal training in engineering.

It also does something specific for the festival. A pandal is a building that exists for five days; the light is what makes the street between the pandals part of the work. Chandannagar's gates and arches turn an entire road into a lit corridor, so that the walking — the parikrama itself — becomes the experience rather than the interval between experiences. Every Bengali who has queued on a wet October night has stood under a Chandannagar panel and watched a picture made of bulbs move, and has probably not known the name of anyone who made it.