A refreshing and felicitous exposition of the universe--explaining how astronomers work, and the logical steps that lead from observation to theory and back. Italian astronomer Rigutti undertook this popularization, he says, because of the rhapsodizing in Italian science writing. Barring occasional grumbles at the bad (which Americans will find gratuitous), he succeeds admirably in his purposes. Rigutti, we quickly learn, is not particularly excited by the solar system; he makes use of the near-in world, however, as a stepping stone to this galaxy and others. A stepping stone literally and metaphorically--because in Part II he very expertly demonstrates how local measurements of distance and apparent magnitude are the basis for the formulas that allow calculations of stellar temperatures, distances, mass, and densities. Here the book approaches a text, and the careful reader can come away with more than a gloss of how astronomers work. The Hertzsprung-Russell diagram (plotting stellar temperatures vs. luminosities) becomes less an article of faith and more a key to understanding the objects--from supernovae to black holes--that populate space. Part III, on stellar evolution, further builds on the H-R diagram. Readers may find it easier to follow (though Rigutti says it's harder to write) because there is now a time-course that is conceptually simpler than the series of separate tracks (spectroscopy, black body radiation, apparent motions, etc.) needed to build to the previous calculations. Rigutti does not deal with the origins or fate of the universe, nor does he name contemporary astronomers--a novelty that seems a plus, given the current spate of American works of this kind. Think of him, in particular, for readers who want more than a bibliographic reference to deeper explanations.