D O C U M E N T 3 4 0 J U L Y 1 9 2 6 3 4 1 The precision is hence significantly lower than we had anticipated. The reason lies in the following: We had expected temperatures below 0° for our measure- ments and had designed our thermostat accordingly. Unfortunately, the 21st of June was very hot and the temperature only dropped to +7° consequently, the feared air movement inside the thermostat occurred. The protective cladding filled with ice and water certainly could not allow temperatures below 0° to penetrate, but at tem- peratures above 0°, convection of the water at 4° below the ice was possible. This evidently occurred as well. Even so, from our experiments we can exclude a Miller effect that rapidly in- creases with distance from the Earth.[3] In addition, and this is probably the main thing for us, we now know that such experiments can be conducted very well in a free balloon. We had absolutely no statical problems e.g., tossing out ballast while the apparatus was running produced motions that are at most at the visibility limit, and yet the oscillations caused by this maneuver are surely a hundred times larger than those that could occur when one remains motionless inside the basket. We would like to repeat the experiment whenever possible and have already or- dered a new protective cladding that will allow the experiments to be conducted in a vacuum. We are hoping to be able to take up these experiments again next winter, provided we are afforded the financial and technical means for the balloon. Then the attainable accuracy will be ten to fifty times greater in any case. As we are spending our vacation in Switzerland, we would feel very honored if it were possible to meet you there. Our Swiss address is: Dr. E. Stahel, c/o Mr. Brugger, 3 Alfred Escher Place, Zurich. In closing, we would again like to express our most obliging thanks to you for the interest with which you have been following our experiments as well as for your letters of recommendation, which were very valuable to us in Germany. Kind regards and greetings, dear professor, respectfully yours, A. Piccard E. Stahel 340. From Paul Epstein [Pasadena,] 31 July 1926 Dear Professor, Upon receipt of your valued letter, regarding Reichenbach,[1] I immediately wrote to two of America’s leading philosophers and asked for their advice. It turns out, though, that both are on vacation. The secretary of one of them wrote me a