The Polarised Ray

1897 · Millimetre-Wave Apparatus · Work 801 of 1,871

A lecture theatre in London on a January evening, gaslight, steep tiers of benches with listeners in dark evening dress seen from directly behind, faces turned fully away, on a lecture table a brass optical bench, at one end a radiator box of brass and dark wood fifteen centimetres long, its brass tube closed by black ebonite, opposite it a small ebonite receiver, wires to a brass mirror galvanometer, its bright light spot on a plain frosted screen, behind the table the man, an Indian man of thirty-eight, wavy dark hair, full dark moustache, dark high-buttoned frock coat, his face toward the camera.

Who
Jagadish Chandra Bose (1858–1937) was a physicist and later a plant scientist, one of India's first scientists in the modern sense. Born in Mymensingh in present-day Bangladesh, he studied in London and Cambridge and in 1885 became the first Indian professor of physics at Presidency College in Calcutta. From 1894 he studied electric waves in a small room next to a college bathroom. He produced waves only five millimetres long and built waveguides, horn antennas and lenses for them that belong to microwave engineering today. In 1904 he received a US patent for a detector made of galena; Walter Brattain, one of the inventors of the transistor, later gave him priority, together with Gerald Pearson, for using a semiconductor crystal as a receiver. Bose then turned to plants and built instruments to measure their growth. His claim that living and non-living matter respond alike to stimuli, and his closeness to spiritual teachings, increasingly made him an outsider among scientists. In 1917 he founded the Bose Institute in Calcutta, and in 1920 he was elected a Fellow of the Royal Society. In India he is honoured to this day as the founder of the country's modern science.
The moment
On Friday, 29 January 1897, Bose gave an invited evening discourse at the Royal Institution in London, with Sir James Crichton-Browne in the chair. His subject was the polarisation of the electric ray. His entire apparatus, galvanometer included, fitted into a case two feet long. The radiator was the size of a small lantern, its tube closed with a thin plate of ebonite; radiator and receiver stood on sliding stands on an optical bench. When the ray struck the receiver, fine wire spirals laid in an ebonite groove, the galvanometer's spot of light swept across the screen. Bose showed that electric rays are refracted and polarised just like light, even by an old railway timetable. He closed with the hope that one day East and West would work together to extend knowledge. The work shows this apparatus of 1897. The galena detector that once stood at this place in the collection was patented only years later.
The other side
That evening Bose was interested in the nature of the waves, not in sending messages. In May 1897 Guglielmo Marconi achieved wireless signalling on Salisbury Plain; the 1909 Nobel Prize for wireless telegraphy went to Marconi and Ferdinand Braun. A radio telegraphy company later asked Bose to stop publishing until a patent deal could be struck. The claim that he had beaten Marconi grew into a legend that his biographer Subrata Dasgupta calls the Bose myth: Oliver Lodge had given similar demonstrations before him. Outside India, on the other hand, Bose long received little recognition.

What the sources leave open: How the lecture theatre was lit and who was in the audience is not recorded; hall and listeners in the picture are typified. The apparatus follows Bose's printed lecture. The face follows a public-domain photograph of Bose at his apparatus, taken in London in 1897 according to one account and in Calcutta according to another. The Bose Institute dates the lecture to 1896, the Royal Institution's proceedings to 1897.

Further reading

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