ABSTRACT
In the preceding chapter we saw how radio emission has now been added to those radiations which may be used by the astronomer in his study of the universe and especially how radio-astronomy has enabled us to probe farther into space than is possible with optical telescopes. We shall here examine in more detail some of these radio emissions which emanate from regions within the Galaxy, with particular reference to the way in which they have demonstrated the presence within interstellar space of various molecules, many of which are present as large, diffuse clouds in certain well-defined galactic regions.
