only points to previous uninterrupted search, continuous following-out of thoughts. "By continuous thinking about it," answered Newton to the question how he had discovered the law of gravitation. Göthe also gives us the same idea in his sentence,
- "What is Invention? It is the end of seeking."
The links which connect isolated thoughts seem indeed to be almost entirely destroyed,—we have to reconstruct them. We see the whole before us only like a faintly outlined or half-washed-out picture, and the painter himself can hardly furnish us with any better explanation of it than we can discover for ourselves. Indeed the comparison holds good in more than one point. In each new region of intellectual creation the inventor works as does the artist. His genius steps lightly over the airy masonry of reasoning which it has thrown across to the new standpoint. It is useless to demand from either artist or inventor an account of his steps.
Observations similar to those made in this single case can be made throughout the whole history of invention, wherever the genius of past generations has busied itself in bringing forward new things. The invention of the steam-engine, for example, stretches back through a whole century,[1] without ever making a step in advance of the natural development going on in other departments of knowledge.
In the school of Galileo,—where his experiments on falling bodies first threw a ray of light through the scholastic cloud which had veiled all knowledge,—there began early in the seventeenth century those experiments in physical science with the growth of which the invention of the steam-engine is inseparably bound up. It is no mere chance that the place is distinguished also as the centre of great artistic development;—art and science nourish together on a rich soil. It is as if the proud citizens of Pisa had made their marble tower to lean expressly for Galileo's experiments. In Florence (1643) Galileo's disciple Torricelli, still in the freshness of youth, made his discovery of the heaviness of the air,—on which there followed directly alarming outcries for the preservation of the "horror vacui" and the whole threatened belongings of the wiseacres of the time. The centre of disputation and investigation passed from Tuscany to
- ↑ See Prof. Reuleaux's Geschichte der Dampfmaschine, Brunswick, 1864.
