John Scott Russell (1808-1882) was a Scottish scientist who first observed and characterised solitons.

I was observing the motion of a boat which was rapidly drawn along a narrow channel by a pair of horses, when the boat suddenly stopped - not so the mass of water in the channel which it had put in motion; it accumulated round the prow of the vessel in a state of violent agitation, then suddenly leaving it behind, rolled forward with great velocity, assuming the form of a large solitary elevation, a rounded, smooth and well-defined heap of water, which continued its course along the channel apparently without change of form or diminution of speed. I followed it on horseback, and overtook it still rolling on at a rate of some eight or nine miles an hour, preserving its original figure some thirty feet long and a foot to a foot and a half in height. Its height gradually diminished, and after a chase of one or two miles I lost it in the windings of the channel. Such, in the month of August 1834, was my first chance interview with that singular and beautiful phenomenon which I have called the Wave of Translation.

The channel was the Union Canal near Edinburgh, and the Wave of Translation is what we now call a soliton, a solitary wave. He remained fascinated with the Wave of Translation for the rest of his life, though his contemporaries did not share his enthusiasm. A soliton can be considered the sum of many waves, all of different frequency. The medium through which the waves pass has different dispersion rates for the different frequencies, and it all works out (thanks to some nonlinearity) that the waves that reach the front are essentially retarded, and the waves that fall behind are advanced.

Among some of his other accomplishments, he designed a new system of hull construction called the "wave line" system, he was the first to experimentally measure the Doppler effect on waves (using sound waves as a train passed), and there is evidence that he attempted to negotiate peace during the American Civil War.

Sources:

http://www.ma.hw.ac.uk/solitons/

http://www.imm.dtu.dk/math_phys/Solitons.html