Notwithstanding the great activity of Defoe's pen (over two hundred pamphlets and books, most of them of considerable length, are known to be his; and it is more than probable that much of his work was anonymous and has perished, or could be only partly disinterred by laborious conjecture) he found time to engage twice in business, once as a factor in hosiery and once as a maker of tiles. In each venture he seems to have been unfortunate, and his business experience is alluded to here only because his practical knowledge of mercantile matters is evident in all his work. Even his pirates like Captain Bob Singleton, and adventurers like Colonel Jack, have a decided commercial flavor. They keep a weather eye on the profit-and-loss account, and retire like thrifty traders on a well-earned competency. It is worth mentioning, however, to Defoe's credit, that in one or two instances at least he paid his debts in full, after compromising with his creditors. Defoe's writings, though all marked by his strong but limited personality, fall naturally into three classes:-- First, his political writings, in which may be included his wretched attempts at political satire, and most of his journalistic work. This is included in numberless pamphlets, broad-sheets, newspapers, and the like, and is admirable expository matter on the public questions of the day. Second, his fiction, 'Robinson Crusoe,' 'Captain Singleton,' 'Colonel Jack,' 'Roxana,' and 'Moll Flanders.' Third, his miscellaneous work; innumerable biographies and papers like the 'History of the Plague,' the 'Account of the Great Storm,' 'The True Relation of the Apparition of One Mrs. Veal,' etc. Between the last two classes there is a close connection, since both were written for the market; and his fictions proper are cast in the autobiographical form and are founded on incidents in the lives of real persons, and his biographies contain a large proportion of fiction.