File consists of a lecture given by Father Burke-Gaffney to a history class at Saint Mary's University on modern European history. The lecture was given twice, oncee to a class taught by Father McCarthy (on 6 November 1952) and once to a class taught by a Mr. Kennedy (25 October 1954). The lecture discusses four astronomers: Nicholas Copernicus, Tycho Brahe, John Kepler, and Galileo Galilei (mainly focusing on Copernicus). The lecture contains handwritten annotations and corrections by Father Burke-Gaffney (he updated it for the 1954 class).