CHAPTER XXI
ANIMATED MACHINERY
IN MARKED contrast to the massive machinery and apparatus described in the last chapter, and fully as wonderful, is a class of machinery to which we might apply the term “animated.” By this we do not mean manikins or toys, but certain higher types of machines which seem to be possessed of powers that we should expect to find only in living beings—machines that have a sense of touch, sight, and hearing—machines that will reason out a mathematical problem; that will talk; that have the equivalent of a memory. In this broad classification we may include such widely different machines as the motion-picture camera and projector, and that mysterious mechanism which seems animated with strange powers of its own—- the gyroscope.
MATHEMATICAL MACHINES
Adding, subtracting, multiplying, dividing, and the working out of complex mathematical problems by machine seems wonderful until we stop to reflect that mathematics is the most precise and mechanical of all sciences. In the simpler forms these machines are mere counting mechanisms in which the counting is done very rapidly by the aid of intermeshing gears. The adding machine is in no sense possessed of any reasoning power, but blindly obeys the simplest of mechanical laws. There are rows of wheels with numbers running from 0 to 9 printed on their peripheries. One wheel represents “digits,” the next “tens,” the next “hundreds,” etc. The wheels are interconnected by means of gearing so that when the digits wheel makes a complete turn, the tens wheel makes 1-10th of a turn, and when the tens wheel completes a rotation the hundreds wheel makes 1-10th of a turn. Keys numbered from “0” to “9” are provided, which respectively turn each wheel through angles from 1-10th to 10-10ths of a rotation. Thus suppose the digit wheel has already been turned through 9-10ths of a rotation and registers the figure “9,” and the “8” key is depressed, the wheel will be given an additional turn of 8-10ths of a rotation and will register the figure “7,” but the tens wheel to the left will also move through 1-10th of a rotation, so that the two wheels will register “17.” Such is the underlying principle of the adding machine, but various refinements are added. For instance, the numbers that are being added are recorded in print, and the total sum of the numbers is not printed until the operator desires to foot up the column.
More complicated, of course, are the mathematical machines which work out involved equations, but they are all based on simple mechanical operations. In the Weather Bureau at Washington there is a tide-predicting machine, which has been called a “great brass brain.” Its brass gears may be set to allow for all the varying factors of apparent solar and lunar motions, and they will work out the tide for any past or future data in a few moments, solving mechanically a mathematical problem that, by hand, would take hours and hours of weary figuring.
HEARING AND TALKING WITH A MECHANICAL “EAR”
It was in 1877 that Edison startled the world with a machine that could actually talk. Others had been working on this problem for years, but they had been trying to copy the human mouth and organs of speech. Edison attacked the problem from a new angle. He was not aiming to produce speech but to reproduce it. Let the human vocal organs modulate the sound waves so that they would produce spoken words; he would provide a machine with no mouth but only an ear and a very retentive memory which would listen to these sound waves and make an impression of them on its soft tinfoil or wax brain. Then, at any time by the principle of “reversal,” the record could be made the transmitter instead of the receiver of sound waves, and it would actuate the ear so that it would repeat the sound vibrations it had formerly received. Thus Edison made the ear of his machine serve the double office of hearing and talking. When Edison’s phonograph was listening it had a sharp needle attached to the ear-drum or diaphragm of the sound box, which cut a hill and dale groove in the brain or cylinder record of the machine; when reproducing, a blunt needle was used which faithfully followed the hills and dales of the groove without cutting a path of its own.