But the mind of the young Galileo was already remarkably acute. He was a good musician, a skilful draughtsman and painter, something of a poet, and had shown considerable talent in designing and building a variety of toy machines. His father soon decided that his son’s bent did not lie in the direction of a dealer in cloths, and, casting about for a scientific career, chose that of medicine for Galileo. So he took up this study at the University of Pisa. One afternoon the youth of eighteen went to the great Cathedral of the city. He knelt to make his devotions. From the roof of the nave hung a large bronze lamp, and as the boy watched he saw an attendant draw the lamp toward him to light it, and then let it swing back again. The swinging caught his attention, and he watched it with more and more interest. At first the arc of the swinging lamp was wide, but gradually it grew less and less. But what struck him as singular was that the oscillations all seemed to be made in the same time. He had no watch, so he put his fingers on his wrist in order to note the pulse-beats. As nearly as he could determine the swings of the lamp as they lessened were keeping the same times. When he went home he began to experiment with this idea of the swinging lamp, or pendulum as it came to be called, and soon had constructed an instrument which marked with very fair accuracy the rate and variation of the pulse-beats. It was imperfect in many respects, but when he showed it to his teachers at the university they were delighted with it, and it was soon generally used by the physicians of the day under the name of the Pulsilogia. But, to his father’s dismay, the young Galileo did not show great interest in the study of medicine. Instead he spent his time studying the mathematics of Euclid, and from them went on to the writings of Archimedes and the laws of mechanics. These latter absorbed him, and fresh from reading them he constructed for himself a hydrostatic balance, the purpose of which was to ascertain accurately the relative proportions of any two metals in an alloy. He wrote an essay on his invention, and circulated it among his friends and teachers. This added to his reputation as a scientist, but brought him no money. His family were poor, and he needed a means of support, and so he applied for, and after a time obtained, appointment to the post of Professor of Mathematics at the University of Pisa. For centuries the laws of mechanics as laid down by the Greek Aristotle had been accepted without much dispute by the civilized world. But a spirit of new thought and investigation was now rising in Europe, and more especially in Italy. Galileo determined to study the laws of mechanics by experiment, and not, as so many earlier scientists had done, by argument or mere theoretical opinions. Therefore he undertook to establish definitely the laws relating to falling bodies.