inch: their object-glasses alone perhaps over thirty inches in diameter, costing thousands of dollars; and then you think of these early astronomers gazing through a hole in a vaulted roof at the tiny specks of light with their naked eye, the work they accomplished appears still more astounding. It is true that their discoveries were at first casual and haphazard. But at last it occurred to one of them that the progress of astronomy depended on continuous observation and the most scrupulously accurate calculations, carefully planned and carried on over a number of years. It was Tycho Brahe who first did this.
You have heard of Copernicus, the Pole, who was really the founder of modern astronomy, because he discovered that the earth went round the sun and was not the center of the universe, as every one had supposed. He died three years before Tycho Brahe was born. Galileo, the famous Italian, was born in 1564 and lived till he was seventy-eight. He made further discoveries about the stars and used a telescope of a very primitive kind. He supported Copernicus's theory with regard to the relative movement of the earth and the sun, and this brought upon him the serious displeasure of the Church. The notion that the earth was not the center of the universe was considered wicked and blasphemous. The Pope commanded him to come to Rome, and after a long trial he was made, under the threat of torture, to retract what he had said. The story is that as he turned
