Printing Presses. Previous

to the Revolution all pre es were built on the same plan—a flat platen, impre ing against type arranged on a flat bed. Impre ions were obtained with a screw, and fifty an hour was the maximum capacity. In 1810 Koenig substituted the revolving cylinder for the platen, and obtained 1,000 per hour in the London Times office. Steam printing pre es were first used by the New York Sun in 1835. Hoe’s pre inventions of 1828 and 1847 made po ible 20,000 per hour, and Craske’s discoveries in 1861 in paptew maché stereotyping increased the rapidity of the pre es. Improvements were continually made in the Hoe, Walter and Bullock pre es, and the first perfecting Hoe pre was erected for the New York Commercial Advertiser in 1880; capacity, 20,000 per hour. 135