Three Copernican Treatises is a collection of three important works by the astronomer Nicolaus Copernicus, who revolutionized our understanding of the solar system. The first work, Commentariolus, is a short summary of Copernicus' heliocentric theory, which proposed that the sun, not the earth, was at the center of the universe. The second work, Letter Against Werner, is a response to the criticisms of the astronomer Andreas Werner, who argued against Copernicus' theory. The third work, Narratio Prima, is a letter from Copernicus' student and assistant, Rheticus, describing his travels to meet Copernicus and learn more about his theories. Together, these three works provide a fascinating glimpse into the development of one of the most important scientific theories in history.This scarce antiquarian book is a facsimile reprint of the old original and may contain some imperfections such as library marks and notations. Because we believe this work is culturally important, we have made it available as part of our commitment for protecting, preserving, and promoting the world's literature in affordable, high quality, modern editions, that are true to their original work.