In the year 1906 one of the oldest and largest firms in the cotton industry, that of Messrs. M‘Connel & Co. Ltd., published, under the title of _A Century of Fine Cotton Spinning_, a brief history of their business, including some deeply interesting extracts from their earliest letter-books. The use of this material in 1913, when a second edition had been issued, by a research student of the University, Mr. W. Bradburn, M.A., prompted inquiries about the original sources and led to the discovery of what is probably a unique set of economic documents--the entire record of a great industrial and commercial enterprise during the forty years of its most rapid expansion. In an upper storey of one of Messrs. M‘Connel’s mills in Ancoats, Mr. Daniels and myself found not only a great array of day-books, cash-books, ledgers and letter-books for the period 1795-1835, but also the whole correspondence, invoices, receipts, etc., of the firm neatly endorsed and carefully packed year by year into tin boxes, each box having the date duly painted upon it. It almost seemed as if the firm had from the first foreseen the lively interest which their achievements would excite in the economic historian of the future, and the fact that one of its early members, Mr. John Kennedy, made a number of valuable contributions to the history of the cotton industry in the Transactions of the Manchester Literary and Philosophical Society and elsewhere lends reasonableness to this supposition. These records were generously placed at the disposal of the University for the purposes of research. They have already enabled Mr. Daniels to cast much new light on the vicissitudes of the cotton trade during the revolutionary and Napoleonic wars, and he hopes in time to illustrate by their aid many aspects of the cotton industry during the most important period of its development. In the meantime a new stimulus has been given to the investigation of origins. These had never been exhaustively studied, and the discovery amongst Messrs. M‘Connel’s business correspondence of a series of original letters of Samuel Crompton which, though written in the year 1812, are concerned with his invention of the mule, more than thirty years before, furnished an additional reason for the reconsideration of the earliest history of the industry which has been attempted in this volume.