Sidereus Nuncias

References:
Sidereus Nuncias or The Sidereal Messenger by Galileo Galilei

Sidereus Nuncias is the text that famously got Galileo imprisoned by the Catholic Church. It is simply a lab wite-up, in which he describes what he saw through his telescope, the moons of Jupiter. The telescope that he used he actually made himself, because the common ones made were not perfect enough for him, magnifying only 3-4X, whereas his magnified 20X. He had to actually teach himself how to make and polish glass lenses for his telescope. The book might very well be the most important scientific book ever written, as it not only changed the Aristotelian view of science, in which only logic was needed to verify science, to a view of empirical evidence.

Galileo made everything perfect in his tests, not wanting anything to be wrong. He waited until it was well past midnight, at its darkest. He even didn’t look through the telescope longer than a brief moment at a time, so that the vapors from his eye wouldn’t fog up the lense.

The book also describes what he saw when he looked at the moon, the mountains and trenches, and his calculations on how tall or deep they were.

The book is full of his illustrations of what he saw, helping to prove the movement of stars and of the moons around Jupiter.