Gallas

African race of many tribes, numbering in all perhaps 3,000,000, living s. of Aby in i a, which they overran in 16th IMG:content-0207.png:[graphic] IMG:content-0208.jpg:[graphic][merged small] recantation of the Coperniçan theory at the age of 69. He early studied the motion of a pendulum and applied it to count the pulse beats. He invented a thermometer, and in 1609 a telescope, the idea probably suggested by the discovery of a Dutch optician. For his defense of the Copernican system he was imprisoned at Rome, made to recant 1633. and forbidden to publish or receive friends. In 1637 he became blind. The most important of his scientific achievements are the discovery of the Laws of Motion and the laying of the foundation of Mechanics.