But in regard to inventions the case is different. I find myself speculating on such a question as this: If Edison had never been born, should we ever have had the phonograph, or the incandescent light? If Graham Bell had died in infancy, should we ever have had the telephone? Or without Marconi should we have had the wireless, or without Morse, the telegraph? Or, to go back still farther, without Franklin should we ever have known the identity of lightning and electricity? Who taught us how to control electricity and make it do our work? One of the questions of Job was, "Canst thou send lightnings, that they may go, and say unto thee, Here we are?" Yes, we can. "We are ready to do your bidding," they seem to say, "to run your errands, to carry your burdens, to grind your grist, to light your houses, to destroy your enemies."
The new inventions that the future holds for us wait upon the new man. The discovery of radium--what a secret that was! But in all probability had not Curie and his wife discovered it, some other investigator would.
Shall we ever learn how to use the atomic energy that is locked up in matter? Or how to use the uniform temperature of the globe? Or the secret of the glow-worm and firefly--light without heat?
The laws of the conservation of energy and of the correlation of forces were discoveries. The art of aviation was both an invention and a discovery. The soaring hawks and eagles we have always been familiar with; the Wright brothers invented the machine that could do the trick.
"Necessity is the mother of invention." As our wants increase, new devices to meet them appear. How the diving-bell answered a real need! The motor-car also, and the flying-machine. The sewing-machine is a great time-saver; the little hooks in our shoes in place of eyelets are great time-savers; pins, and friction matches, and rubber overshoes, and scores on scores of other inventions answer to real needs. Necessity did not call the phonograph into being, nor the incandescent light, but the high explosives, dynamite and T. N. T. (trinitrotoluol) met real wants.
The Great War with its submarines stimulated inventors to devise weapons to cope with them. Always as man's hand and eyes and ears have needed reënforcing or extending, his wit has come to his rescue. In fact, his progress has been contingent upon this very fact. His necessities and his power of invention react upon one another; the more he invents, the more he wants, and the more he wants, the more he invents.