It is well the reader should understand the conditions under which it would seem these messages were sent. Somewhere within the moon Cavor certainly had access for a time to a considerable amount of electrical apparatus, and it would seem he rigged up⁠—perhaps furtively⁠—a transmitting arrangement of the Marconi type. This he was able to operate at irregular intervals: sometimes for only half-an-hour or so, sometimes for three or four hours at a stretch. At these times he transmitted his earthward message, regardless of the fact that the relative position of the moon and points upon the earth’s surface is constantly altering. As a consequence of this and of the necessary imperfections of our recording instruments his communication comes and goes in our records in an extremely fitful manner; it becomes blurred; it “fades out” in a mysterious and altogether exasperating way. And added to this is the fact that he was not an expert operator; he had partly forgotten, or never completely mastered, the code in general use, and as he became fatigued he dropped words and misspelt in a curious manner.