We are less likely to do anything without proper need for it. It is the need that makes an invention possible. The ancients used to illustrate the fact that great need stimulates the inventive powers, by the story of the raven in a drought. This wise bird, we are told, found water low down in a hollow tree, but was unable to enter the narrow passage that led to the water. In this predicament it would have died of thirst, if it had not thought of raising the level of the water by dropping many stones one after another into the hollow of the tree. In this way it was able to drink water.
The necessity of defence against wild beasts taught primitive man to make flint-heads for his weapons, to invent the blow-pipe and bow-and-arrow. The necessity of obtaining shelter against the inclemency of the weather taught him to build houses and clothe himself in the skins of wild beasts. As life without fire was almost impossible, he invented various ways of producing sparks by the rapid friction of hard pieces of wood. In this way he obtained the means of cooking his food. But at first the art of boiling was beyond his powers, as he had no vessels capable of resisting fire.
This difficulty was solved in some cases by the ingenious method of stone boiling. The food to be cooked was placed on skins or wooden vessels containing water, and the water was heated by dropping into it stones heated at a neighboring fire. In this and in many other ways we may imagine that most of the early inventions of mankind were the result of the pressure of need. Thus snowshoes and skates and sledges were invented as means of crossing the snow and ice with which land and sea are covered for the greater part of the year in the extreme north. Necessity teaches the inhabitants to construct tanks capable of containing enough rain-water to last through the whole year. The natives of Greenland, having no glass, make themselves windows of the entrails of whales and dolphins; and for want of iron nails fasten together the planks of their trail fishing-boats with the sinews of the seal. In countries where coal and wood are scarce, we find bones and dung used as fuel. Indeed, it would require a large volume merely to enumerate the various ways in which the inventive power of man all over the world. encounters the necessities imposed upon him by the harshness or niggardliness of nature.
Wonderful inventions that have been made by men whose chief object was the satisfaction of their intellectual curiosity. It cannot be said that no imperious necessity led to the invention of, the photographic camera or of the spectroscope. Even the telegraph and the steam-engine, in spite of their immense practical utility, can hardly be regarded as necessities of existence, seeing that the human race managed to do without them so long and never seriously felt the need of them.
The complicated system of modern civilization the greatest amount of inventive work is done by a leisure class, the members of which have plenty of time and money to devote to the work of discovery. In short great inventions, as we have observed in most of the cases, were made under the pressure of the need. However, there might be some other inventions that can just be called us accidental inventions as the discovery of Penicillin by Fleming.