I N T R O D U C T I O N T O V O L U M E 1 5 l x x x i x Einstein was filed with the German Patent Office on 13 September ([35 558]).[57] Other applications had been filed with the Patent Office in March (S73730.1/17a) and October, the latter design possessing a water steam jet refrigerant, but further details on the patents are unknown. A third application on an absorption-diffusion cooler was submitted on 26 October (patented as DE499830). In October, Szilard approached Bamag-Meguin Co. and offered the firm three cooler inventions for purchase, financing, development, production, and sales. He entrusted his brother, Béla (Adalbert), to enter into negotiations in person ([35 560] and Abs. 624) and drafted a contract with the company (Abs. 633 and 634). After discussions with general director H. Peiser, he drew up a second draft contract (Doc. 417 and Abs. 649). Meanwhile an application on another absorption cooler was submitted on 16 December.[58] In April 1927, Szilard was working hard on fitting a “mercury pump” in a refrig- erator (Doc. 512). This pump was his own invention: an arrangement for “pouring molten metals into a mold by using electric current,” for which he had submitted an application on 20 January 1926 (patented as DE 476812). He also considered the time to be ripe for entering into a written agreement with Einstein on how to share income from the refrigerators (Abs. 814). In view of Szilard’s intense activity in this cooperation, and Einstein’s few let- ters, it is difficult to establish Einstein’s contributions. The capillary pump seems to have been his idea. “I am happy […] about the capillary pump”— he wrote to Szilard on 15 September 1928 —“for which I have not yet succeeded in arousing your enthusiasm” [21 432]. But their exchanges must have been quite frequent, since Szilard noted, “soon you will be getting sick enough of ice machines” (Abs. 649). Whatever they had achieved by late spring of 1927 would be only the first stage of their future collaboration. XI. A Hectic Pace of Life Despite having tried in previous years to minimize public appearances and obliga- tions, the rapid pace of Einstein’s private and professional life seemed unrelenting.[59] In October 1926, he confided to Zangger that “so much keeps assailing me that I rarely have time for myself” (Doc. 397). His celebrity status did not help matters and irked him at times. Thus, he asked Friedrich S. Archenhold, director of the Treptow Observatory in Berlin, not to involve him publicly in a planned exhibition about the planet Mars, adding in exasperation: “Can you under- stand that I’m tired of appearing everywhere as a symbolic bellwether with a halo? So, leave me out of it!” (Doc. 394). He thought his work was suffering: “I myself have not managed to do anything of notable good. The muses tend to grant their