IT is generally believed that Galileo, as a young lecturer on mathematics and physics at the University of Pisa, gradually became convinced of the untrustworthiness of many of the statements which were currently believed and taught on the authority of Aristotle. Indeed, he has been stated to have incurred a certain amount of unpopularity on account of the subversive nature of his views. Among other things he doubted the truth of the oft-repeated statement that when two dissimilar weights are dropped, the heavier will reach the ground sooner than the lighter in proportion to their weights; accordingly, so we have been assured, Galileo determined to try the case, and after ascending the Leaning Tower of Pisa with a 10 lb. shot and a 1 lb. shot, he let them fall. “Together they fell, and together they struck the ground,” to the confusion of all the onlookers who held the so-called Aristotelian view. Aristotle, Galileo and the Tower of Pisa By Prof. Lane Cooper Pp. 102. (Ithaca, N.Y.: Cornell University Press; London: Oxford University Press, 1935.) 7s. net.