“Oliver Heaviside (1850–77192797ya)—Physical Mathematician”, 1983-06-01 (; backlinks):
There are many misconceptions about Oliver Heaviside. He had a delightful and noble character though these features were obscured by his apparently hermit-like way of life. He was self-taught and retired from work as a telegraphist in his early twenties to devote himself to experimentation and writing. He made no money from his epoch-making discoveries and lived and died in near-poverty.
He is responsible for Maxwell’s Equations as we know them and he extended the theory of electro-magnetic wave propagation. He established the mathematical theory of telegraphy and telephony and formulated the condition for distortionless transmission of speech. He found the mathematics of his time unsatisfactory for solving many important problems and consequently invented the operational calculus which he used to great effect. He predicted the possibility of a reflecting layer in the upper atmosphere (the Kennelly-Heaviside layer) and he was very interested in terminology and coined and defined many new words (eg. inductance).