In the last number of the Classical Quarterly (July-October, 1920, p. 172) Dr. Holmes has asked if a trustworthy observer has ever seen with the naked eye a moon not more than 27 hours old in an atmosphere no clearer than that of Geneva. Hoping that I am a trustworthy observer, I will enumerate the cases where I have observed crescents of an age less than 27 hours. I have also constructed tables with which I find the moment when the moon becomes visible. I believe the minimum for Heidelberg is 20 hours from February 1 to April 1, if the moon is at her perigee and the argument of latitude is between 60° and 120°. All times given here are mid-European time ( = Greenwich mean time+1 hour). I have never used a binocular. Heidelberg is 35 m. east of Greenwich, and 25 m. west of the mid-European meridian.