This work presents, in English translation, the great discoveries in mathematics from the Renaissance to the end of the nineteenth century. You are able to read the writings of Newton, Leibniz, Pascal, Riemann, Bernoulli, and others, exactly as the world saw them for the first time. Succinct selections from 125 different treatises and articles, most of them unavailable elsewhere in English, offer a vivid, firsthand story of the growth of mathematics. The articles are grouped in five sections: I. The Field of Number. Twenty-four articles trace developments from the first steps in printed arithmetic through selected number systems, to the early phases of modern number theory. II. The Field of Algebra. Eighteen articles on algebra include writings by Fermat, John Wallis, Newton, Leibniz, Abel, Galois, etc. III. The Field of Geometry. Thirty-six articles on geometry span 500 years. Here are the early writers such as Fermat, Desargues, Pascal, and Descartes; and some of the men who revived the study in the nineteenth century and developed non-Euclidian forms: Lobachevsky, Bolyai, Riemann, and others. IV. The Field of Probability. Selections from Fermat, Pascal, De Moivre, Legendre, Chebyshev, and Laplace discuss crucial topics in the early history of this branch of modern mathematics. V. The Field of Calculus, Functions, and Quaternions. The development of the calculus, function theory, and quaternions is covered from early sources of calculus to important advances relating to the commutative law in quaternions and Ausdehnungslehre. This section contains works of Bessel, Mobius, W. R. Hamilton, Leibniz, Berkeley, Cauchy, Fermat, and six other pioneering mathematicians. Each article is preceded by a biographical-historical Introduction.