This is a collection of two unrelated novels. The City and the Stars is one of my favorite Clarke novels. It centers on Alvin, the first child born in ten million years in Diaspar, the city of the title, the last city on Earth. He's a "unique" rather than someone reborn from the Hall of Creation, and unique in wanting to go beyond the bounds of the city. Diaspar is a completely enclosed and stagnant culture, on an Earth so old the oceans are gone and there's no longer a moon. In paperback this is a slim, fast reading book of 196 pages. It’s well-written, thought-provoking and makes a good introduction to Clarke. It deals with a lot of his trademark themes of transcendence, immortality and exploration and is interesting and unusual in treating of a far future Earth. I actually prefer this book to more famous Clarke novels such as Childhood's End and Rendezvous with Rama.
The Sands of Mars centers on Martin Gibson, a science fiction writer who visits the Martian colony. Published in 1951 naturally a lot of the scientific details are dated--we know much more about Mars today, on which we currently have a robotic presence. And I don't think this book excels in memorable characters or plot. But Clarke is good at making you feel a sense of awe and enthusiasm at the exploration of space. So it's a readable book, but not comparable to The City and the Stars, Childhood's End or a collection of his short fiction as an introduction to him.
