The telegraph disappears. The sewing machine, reaper, and thresher have passed away, and so also have all india-rubber goods. We no longer see any photographs, photo-engravings, photolithographs, or snap-shot cameras. The wonderful octuple web perfecting printing press; printing, pasting, cutting, folding, and counting newspapers at the rate of 96,000 per hour, or 1,600 per minute, shrinks at the beginning of the century into an insignificant prototype. We lose all planing and wood-working machinery, and with it the endless variety of sashes, doors, blinds, and furniture in unlimited variety. There are no gas-engines, no passenger elevators, no asphalt pavement, no steam fire engine, no triple-expansion steam engine, no Giffard injector, no celluloid articles, no barbed wire fences, no time-locks for safes, no self-binding harvesters, no oil nor gas wells, no ice machines nor cold storage. We lose air engines, stem-winding watches, cash-registers and cash-carriers, the great suspension bridges, and tunnels, the Suez Canal, iron frame buildings, monitors and heavy ironclads, revolvers, torpedoes, magazine guns and Gatling guns, linotype machines, all practical typewriters, all pasteurizing, knowledge of microbes or disease germs, and sanitary plumbing, water-gas, soda water fountains, air brakes, coal-tar dyes and medicines, nitro-glycerine, dynamite and guncotton, dynamo electric machines, aluminum ware, electric locomotives, Bessemer steel with its wonderful developments, ocean cables, enameled iron ware, Welsbach gas burners, electric storage batteries, the cigarette machine, hydraulic dredges, the roller mills, middlings purifiers and patent-process flour, tin can machines, car couplings, compressed air drills, sleeping cars, the dynamite gun, the McKay shoe machine, the circular knitting machine, the Jacquard loom, wood pulp for paper, fire alarms, the use of anæsthetics in surgery, oleomargarine, street sweepers, Artesian wells, friction matches, steam hammers, electro-plating, nail machines, false teeth, artificial limbs and eyes, the spectroscope, the Kinetoscope or moving pictures, acetylene gas, X-ray apparatus, horseless carriages, and--but, enough! the reader exclaims, and indeed it is not pleasant to contemplate the loss. The negative conditions of that period extend into such an appalling void that we stop short, shrinking from the thought of what it would mean to modern civilization to eliminate from its life these potent factors of its existence. Returning to the richness and fullness of the present life, we shall first note chronologically the milestones and finger boards which mark this great tramway of progress, and afterward consider separately the more important factors of progress. CHAPTER II. CHRONOLOGY OF LEADING INVENTIONS OF THE NINETEENTH CENTURY. 1800--Volta’s Chemical Battery for producing Electricity. Louis Robert’s Machine for Making Continuous Webs of Paper.