15 June 1926
Many thanks for your letter of the 11th which brought us your most welcome acceptance. Besides that it once again communicates news that will make the heart of every theoretical physicist leap for joy. But we will be able to talk more about that when you are here; there are always many questions to be asked, for the appetite increases with eating. Just take care not to overwork. And so I await the announcement of your arrival time on the 15th of July. The earlier, the better. You lecture to the Physical Society6 then on the 16th, and on the 17th to our Colloquium. On the evening of the 17th I hope to have several colleagues and you at our home. For all eventualities I repeat that I shall be in Bonn from the 5th to the 11th of July. My address, however, remains the usual one.