Charles Wheatstone (1802-1875), English physicist and inventor, first became known for his work in acoustics, inventing the concertina in 1829. In 1837 he and William Cooke (1806-1879) took out a patent for an electric telegraph, which was used in the world's first public telegraph service. In 1841 Wheatstone built the first printing telegraph and in 1845 devised the first single-needle telegraph. It was in a paper to the Royal Society in 1838 that Wheatstone first explained the principle of the stereoscope, a piece of equipment he had been developing.
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