Many times during the past months, while reading your really remarkable magazine, I have come across contradictions in explanations throughout the stories, which, while not very serious, tend to give me the impression that the Authors either did not care about or did not see through the errors they committed. I did not complain about them, considering them but minor mistakes. But in Ray Cummings' latest current novel, "The Exile of Time," there exists such a monstrosity as I believe calls for an explanation. Mr. Cummings' story, you know, centers around his time-traveling machine. If such a thing were possible, would it not be reasonable to believe that a holder of the secret of time-traveling could go back into the past and prevent some catastrophe or tragedy as his historical knowledge of the event would make possible? According to this theory then, a person could go back into the past and divert the hand of Wilkes Booth on April 15, 1865, about to assassinate Lincoln. But this shows its own impossibilities: that of two contradicting absolute truths for the world to believe. Likewise, a person could travel into the future, learn of his own death, go back into his own time and take measures to prevent it. In the same way, this could not be. [But Mr. Cummings explains that these things are impossible.--_Ed._] I do not mean to be critical, but it would lend much more interest to the story if the authors would be a bit more careful.--Robert W. Conrad, Rush City, Minn. _Tripe?_ Dear Editor: In the short time your mag. has been out, it has already established itself as the best in the field. I got a real kick out of most of your stories. In the May issue, two yarns are outstanding: Charles W. Diffin's splendid "Dark Moon" and Nat Schachner and Arthur L. Zagat's especially fine "The Death Cloud." These two are as thrilling stories as I have ever read. Mr. Diffin I've read before and always enjoyed; but Messrs. Schachner and Zagat are new to me. I am looking forward to seeing more of their stuff. But what has happened to Cummings? He used to be aces up, but now comes this tripe of his called "The Exile of Time"; especially the current installment with its long-winded rot about mysticism and theosophy and the Lord knows what. Where was the Editor when this blew in? Surely there are plenty of Swami sheets for that truck; it has no place in Astounding Stories. Give us more of Diffin, Leinster, Schachner, Zagat and Rousseau, and you'll keep us all satisfied.--D. Kay, Standish Arms, Brooklyn, N. Y. _For Rocket Fans_ Dear Editor: