Paper, 'On Operators in Physical Mathematics. Part I.' by Oliver Heaviside Heaviside writes on the 'Connexion between a flux and a force through an operator', the 'Determinateness of a solution through the operator', 'Electromagnetic operators', 'Operators admitting of easy treatment', 'Solutions for simple harmonic, impulsive, and continued forces', 'Partial fractions and normal solutions', 'Decomposition of an operator into a series of wave operators', 'Treatment of an irrational operator. Solutions in ascending series', 'Transformation to a descending series', 'Fractional differentiation', 'Differentiation generalized', 'The inverse factorial function', 'Interpretation of vanishing differential coefficients', 'A suggested cosine split', 'The exponential theorem generalized', 'A Bessel function generalized', 'The binomial theorem generalized', 'Taylor's theorem generalized', 'Special formulae for factorials', and a 'Property of the generalized exponential'. Annotations in pencil and ink. Subject: Mathematics Received 15 December 1892. Read 2 February 1892. A version of this paper was published in volume 52 of the Proceedings of the Royal Society as 'On Operators in Physical Mathematics. Part I.' 1892