All About Engines

The Pioneers before Watt 25 contrivance can be made out of a half-pound coffee tin, a couple of pieces of copper tubing, some stiff wire, solder, and a soldering iron. In this and the glass-form boiler and rotating portion are in the same piece. For sixteen hundred years after Hero’s inven- tion there was no further progress. Books were scarce and, until the invention of printing in 1445, had to be copied laboriously by hand, so that few could possess them. Moreover, the Great Schism separated the Eastern and Western sections of the Roman Empire, and the stores of ancient learning remained jealously guarded in the East, while Western Europe was sunk in barbarism. But with the sack of Constantinople by the Ottoman Turks in 1451, scholars and manuscripts flowed westwards, and in Italy especially there was a new enthusiasm for learning. The Italian scholars, however, were not content to accept the mere statements of the old writers without question. Where these dealt with mechanics or natural science they were put to the test of ex- periment. Old explanations were found to be wrong and new facts were added to knowledge. Galileo, watching a hanging lamp swinging slowly to and fro in the cathedral, and timing it by the beat of his pulse, discovered the law of the pendulum—that if the swings are small they are completed in equal times. Dissatisfied with the statement that heavier bodies fell to the ground more rapidly than light ones, he allowed bodies of different weights to drop