Page:Popular Science Monthly Volume 52.djvu/277

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S the nineteenth century draws to its close there is no slackening in that onward march of scientific discovery and invention which has been its chief characteristic. Far from it, discovery and invention seem to be proceeding with ever-increasing rapidity; it is as if a fountain had been opened which, far from showing signs of exhaustion with lapse of time, gained in volume and force from year to year. Whether a pause will ever come is a question which many would be disposed to answer in the negative. It seems impossible that Nature, now that we have discovered the true method of interrogating her, should not go on revealing herself to us with greater and greater fullness. Without speculating, however, too deeply on the future, we may affirm that at present the scientific movement is at its maximum of vigor and productiveness.

It is astonishing to look back and see the strides that have been made in eighty or ninety years. In the beginning of the century there were stationary steam engines, and a few crude attempts were being made in the direction of steam navigation; but as yet the locomotive was a thing unthought of. To-day marine navigation has taken the form we see in the giant vessels that ply between this country and Europe and the first-class battle ships of the world's great navies, with their triple expansion engines, their wonderfully perfected boilers, their twin screws, and their infinitely multiplied appliances for safety and efficiency.

At the beginning of the century electricity was a curious study, giving only slight promise of any useful practical applications. It had not advanced beyond the frictional machine, the Leyden jar, and the voltaic pile. The telegraph was as yet undreamed of, and the telephone and the dynamo utterly unimaginable developments. Had any one dared to conceive that signals could be made to pass in a second of time between Europe and America he would have been considered a fit candidate for Bedlam; and certainly not less insane would have been considered the notion that a human voice could by any device make itself distinctly audible at a distance of five hundred or even a thousand miles. To-day these things are commonplaces, and men are beginning to grudge the trouble of putting up wires for the conveyance of the electric current, great authorities in the scientific world having told them that theoretically it ought to be possible to do without such crude appliances. What was a curious toy in the beginning of the century is the jack-of-all-work at its close, or, in other words, the most widely available form of force in the modern world. What steam can not do, owing to the difficulty, on the one hand, of generating it locally, and, on the other, of conveying it to any great distance, electricity, which is capable of infinite subdivision and of distribution from a relatively distant center, stands ready to undertake.

We have only to look around us to see the innumerable wonders that science in its practical applications has wrought, and to be impressed by the beneficence of its operations. The electric light in our streets and the familiar trolley car constitute