D O C U M E N T S 3 2 7 , 3 2 8 A U G U S T 1 9 2 2 2 6 1 326. From Helene Stöcker[1] Nikolassee-Berlin, 14 August 1922 [Not selected for translation.] 327. From David Hilbert Göttingen, 15 August 1922 Dear Colleague, The daughter of my old patron and friend who recently died at an advanced age, Leo Königsberger (Heidelberg),[1] is married to a physician in China, Dr. Pfister.[2] She asks me to convey to you the enclosed invitation from her husband.[3] As I hear, you are not going to Leipzig [4] I regret it the more so, since I have not spoken to you for so long[5] and do not see any occasion to visit you myself in Ber- lin. Thus I take this written route to wish you a successful and productive journey replete [with] impressions and pleasures! Most cordial regards, yours, D. Hilbert. 328. From Hermann Anschütz-Kaempfe Lautrach manor, 20 August 1922 Dear, esteemed Professor Einstein, Many thanks for your letter of the 14th and your postcard of the 17th of this mo. Single-phase motors work best with inductive and ohmic resistance, so it would perhaps be advisable not to dispense with the ohmic one, after all. The energy loss is not such that it would tip the balance much it is merely a question of heat gain, which the carrying off seems to have solved. I had the next device sketched so that I install the blow magnets inside the sphere and the two half-shells (in which the electro-inductive resistance sits) perfectly symmetrically close around the sphere this way I obtain a somewhat better efficiency, because I can make the spherical shell out of copper instead of aluminum additionally, the danger that the force lines penetrate through the sphere and cause disturbances in the gyro’s iron parts is avoided. One disadvantage is the larger flow of current between the electrodes, but the good suitability of the graphite-rubber coating now makes it worth risking. Per- haps it is also possible to use the two blow magnets as inductive resistors for the two gyros at the same time it is possible that with this arrangement one can even