But there are many hundred copies to be despatched by the morning mails. Manchester and Glasgow would be frightened from their propriety, if the daily London papers did not arrive at the accustomed hour. The London merchant, banker, lawyer, would go unwillingly to his morning labour, if he had not had one passing glance at the division in the House, the state of the money-market, the last foreign intelligence. Late as the paper may have been in its mental completion, Manchester, Glasgow, and London will not be kept without that illumination which has become almost as necessary as sunlight. Machinery has been created by the demand, to carry the demand farther than the warmest imagination could have anticipated. In 1814, Koenig, a German, erected the first printing-machine at the "Times Office," and produced eighteen hundred impressions an hour on one side. The machine superseded the duplicates of the type which were once necessary, painfully and laboriously to keep up a small supply, worked by men, with relays, at the rate of five hundred an hour. In 1818 Edward Cowper produced his cylinder-machine, which effected a revolution in the commerce of books; and, in connexion with the paper-machine, enabled the principle of cheapness to contend against an impolitic and oppressive tax. This is still the machine in general use for many newspapers and much book-printing. We will briefly describe the operation of printing a sheet of paper on both sides by this instrument. Upon the solid steel table at each end of the machine lie the pages which print one side of the sheet. At the top of the machine, where the laying-on boy stands, is a heap of wet paper. The signal being given by the director of the work, the laying-on boy turns a small handle, and the moving-power of the strap connected with a steam-engine is immediately communicated. Some ten or twenty spoiled sheets are first passed over the types to remove any dirt or moisture. If the director is satisfied, the boy begins to lay on the white paper. He places the sheet upon a flat table before him, with its edge ready to be seized by the apparatus for conveying it upon the drum. At the first movement of the great wheel, the inking-apparatus at each end has been set in motion. The steel cylinder attached to the reservoir of ink has begun slowly to move,--the "doctor," or more properly "ductor," has risen to touch that cylinder for an instant, and thus receive a supply of ink,--the inking-table has passed under the "doctor" and carried off that supply,--and the distributing-rollers have spread it equally over the surface of the table. This surface, having passed under the inking-rollers, communicates the supply to them; and they in turn impart it to the _form_ which is to be printed. All these beautiful operations are accomplished in the sixteenth part of a minute, by the travelling backward and forward of the carriage or table upon which the _form_ rests.