In giving a course of recent wireless talks, I assumed that my listeners had no previous scientific knowledge of any kind, and tried to introduce them to the fascination of modern astronomy and to the wonder of the universe we see through the giant telescopes of to-day.

The present book contains these talks expanded to double their original length, still in the informal conversational style and simple non-technical language of wireless talks. It is totally unambitious, aiming only at providing an easy, readable and not over-serious introduction to the most poetical of the sciences.