Note: First published in Astounding Science-Fiction, May 1938. Letter to the editor John Campbell as regards to an article by Leo Vernon. The letter is discussed in Astounding Days (1989) but is not reprinted in the Appendix of this volume. The version in Ascent to Orbit (1984) is a facsimile of the original, but it's poorly reprinted and barely readable.

Synopsis: Withering criticism of Leo Vernon's knowledge of rocketry and mathematics as expressed in an article called ''Rocket Flight'' in the January issue of Astounding Stories.