ABSTRACT
In whatever literary projects they were engaged Marx and Engels were accustomed to work in close co-operation. Engels gave his friend every possible assistance when he was writing his major work on the capitalist system.1 Marx often consulted Engels on theoretical and practical problems. Engels had studied economics and had written an essay on "Outlines of a Critique of Political Economy" in the Deutsch-Franzosische Jahrbiicher in 1844.2 His wide reading and practical knowledge of business enabled him to offer valuable comments upon Marx's criticisms of the classical economists as well as upon Marx's own economic doctrines. Engels also gave Marx considerable help by supplying him with information concerning the cotton industry. Marx had no experience of the business world and he relied upon Engels for information concerning the running of an office or a factory. Sometimes Engels passed Marx's queries on to others. On Engels's advice Marx wrote to Henry Ermen for data concerning cotton spinning as practised in the Bridgewater Mill at Pendlebury.3 The information that he received appeared in Marx's discussion of the rate of surplus value in the third part of the first volume of Das KapitaJ.4
