The Incandescent Light.—The first electric incandescent lamp that was made used a platinum wire for the filament. J. W. Starr substituted a carbon filament for the platinum wire, but the first successful incandescent lamp was produced by Edison in 1879 after he had made over 2000 experiments in order to find a suitable fiber for the filament. In order to be able to use the incandescent lamps, Edison designed a new system of distributing the current through several circuits and between any number of lamps.
The lamps of to-day have filaments of tungsten and these are sealed in bulbs filled with nitrogen and which together greatly increases the candle-power and at the same time uses less current. In 1882 the Pearl Street Edison station in New York was put into service and was the first of the great central stations. The Commonwealth Edison Company of Chicago is the largest electric lighting system in the world. There are four stations and together they have an output of 320,000 kilowatts, or 430,000 horsepower.
The Electric Railway.—The first attempt to build a railway operated by electricity was made by Thomas Davenport, a Vermont blacksmith in 1835. Next, C. T. Page made a sixteen horsepower electric locomotive in 1850 and when it was tried out on the Baltimore and Ohio Railroad it ran at a speed of nineteen miles an hour. Batteries were used in both cases to supply the current.
The Trolley Car.—The first practical overhead electric line was shown in Chicago in 1883 by C. J. Van Depoele and about the same time Leo Daft built a third-rail line from Saratoga Springs, N. Y., to Mount McGregor, while a conduit line was built by Bently and Knight in Cleveland, Ohio. In 1884 the first practical trolley line was built in Kansas City and from this time on horse- and mule-drawn cars were doomed, except on West Street in New York City where they are still used to hold down a franchise.
There were in 1912 about 41,000 miles of track operated by electricity in the United States; over 76,000 passenger cars were in service and 12,100,000 passengers were carried, all of which goes to show that there is money in electrical inventions for somebody.
The Electric Locomotive.—The 1913 type of electric locomotive used on the New York Central is fifty-seven feet long, weighs 110 tons, has eight motors of 325 horsepower each, which are mounted on four trucks and driving eight axles. This powerful locomotive is capable of hauling a train of 1200 tons at a speed of sixty miles an hour on a straight level track. The stockholders of the General Electric Company of Schenectady, N. Y., profited by their building.
The Linotype.—The linotype is a machine that is operated like a typewriter and makes a slug or a solid line of type from metal type-bars each of which has a letter on it. These type-bars are then properly spaced and melted type metal is run into the matrix they form. This wonderful machine is the invention of Ottmar Mergenthaler who began working on it in 1876 and completed the machine in 1886. Thousands of linotype machines are in use at the present time and it goes without saying that the inventor was richly rewarded for his hard labors.
Moving Pictures.—The moving-picture industry, which is the third largest in the United States, came into being through the following inventions: In 1845 a toy called the zoetrope, or wheel-of-life, was invented; it was so made that when a series of drawings showing the different positions of, say, a horse in motion was viewed through a number of vertical slits in a rapidly revolving cylinder the horse would appear to be running. It was truly a moving picture.
The next step was taken by Eadweard Muybridge in 1877, who was the first to make a series of instantaneous photographs of a horse in motion, and in this way he showed the true position of the animal at different instants of its gait, but since there was no exactness in timing the intervals between the exposures of the dry plates—the film had not yet been invented—they could not have been used for moving pictures.
The photographic gelatine film having come into use, Edison, in 1893, invented two machines, the kinetograph which was a camera for taking successive pictures of moving objects, and the kinetoscope which allowed the pictures made on the film by the kinetograph to be viewed. The kinetoscope showed each picture on the film to the eye for about ¹/₄₀th of a minute, so that the figures seemed to move as in actual life. And this is the way the moving-picture industry was born. It was easy to combine a projecting lantern and a kinetoscope so that the little photographs on the film could be thrown on a screen and enlarged and this is the principle of all moving-picture machines as they are now constructed.