spite of their great wealth of external appliances.

As the wave-length of a Hertzian (electric) ray was very large--about 3
metres[8] long--compared with that of visible light, considerable
difficulties were experienced in carrying on experiments with the same.
It was thought, for instance, that very large crystals, much larger
than what occur in nature, would be required to show the polarisation of
electric ray. Prof. Bose who 'combined in him the inventiveness of a
resourceful engineer, with the penetration and imagination of a great
scientist'--designed an instrument which generated very short electric
waves with a length of about 6 millimetres or so. And, by working with
Electric radiations having very short wave-lengths, he succeeded in
demonstrating that the electric waves are polarised by the crystal
_Nemalite_ (which he himself discovered) in the very same way as a beam
of light is polarised by the crystal Tourmaline. He then showed that a
large number of substances, which are opaque to Light (_e.g._ pitch,
coal-tar etc.) are transparent to Electric Waves. He next determined the
Index of Refraction of various substances for invisible Electric
Radiation and thereby eliminated a great difficulty which had presented
itself in Maxwell's theory as to the relation between the index of
refraction of light and the di-electric constant of insulators. He then
determined the wave length of Electric Radiation as produced by various
oscillators.

HIS EARLY CONTRIBUTIONS AND THEIR APPRECIATIONS

His first contribution was 'On Polarisation of Electric Rays by Double
Refracting Crystals.' It was read at a meeting of the Asiatic Society of
Bengal, held on the 1st May 1895, and was published in the Journal of
the Society in Vol. LXIV, Part II, page 291. His next contributions were
'On a new Electro polariscope' and 'On the Double Refraction of the
Electric Ray by a Strained Di-electric.' They appeared, in the
_Electrician_, the leading journal on Electricity, published in London.
These 'strikingly original researches' won the attention of the
scientific world. Lord Kelvin, the greatest physicist of the age,
declared himself 'literally filled with wonder and admiration for so
much success in the novel and difficult problem which he had attacked.'
Lord Rayleigh communicated the results of his remarkable researches to
the Royal Society. And the Royal Society showed its appreciation of the
high scientific value of his investiga