Excerpt:
A century ago, at the height of what might be referred to as the "canal furor," Camille Flammarion published the first volume of his great work, La Planète Mars, which summarized what was then known about the planet. In his preface he described how he hesitated between two methods of presenting the state of Martian knowledge---in special chapters dealing with topics such as continents, seas, polar caps, and so on; or chronologically, in the order in which the facts had been obtained. He at length decided on the latter approach, "mainly," he wrote, "because it seemed to me to be the more interesting . . . and also because it provides a better account of the gradual development of our knowledge." So it has seemed to me, and I have done likewise.