Sidereal Messenger and Kepler's Dioptrics

PREFATORY NOTE.

of his astronomical discoveries so interesting, both in matter and in style, that I translated it as a recreation A leisure activity or hobby pursued outside of one's professional duties. from school-work. I venture to think that others also will be interested in following Galileo through the apprehension The act of understanding or grasping a new concept; here, it refers to the moment Galileo first perceived these celestial truths. of his famous discoveries, and in reading the language in which he announced them.