Beschreibung:

EINSTEIN, ALBERT. Autograph letter signed ("Papa") to Hans Albert Einstein, n.p. [Berlin], 9 December 1917. 2¼ pages, 8vo, 223 x 140 mm. (9 x 5½ in.), page 1 incorporating two carefully labeled geometrical diagrams . EINSTEIN HELPS HANS ALBERT WITH PLANE GEOMETRY Einstein sent exercises in geometry to Hans Albert, but a censor has unexpectedly broken into their correspondence: "...The funniest part of your letter was a postscript, which was not from you but from the censor. He gave the solution to my exercise, omitted by you, absolutely correctly, in pencil below your letter..." Einstein gives a detailed description of the problem in plane geometry, with diagrams, and continues: "...I have sent you five very good, interesting books for Christmas...They belong to you and Tete together. I have not divided them between you. Reading and understanding, not owning, books, is the main thing" Hans Albert should let him know when the books arrive -- "Everything now is so unsure!" -- and should tell him when Eduard comes home from his stay in a sanatorium. It is time for Eduard to start to school, but he should not be placed with the youngest children, where he will be bored. As for himself, "My health is all right, but my digestion has became so sensitive and weak, that I have to feed myself like a little child. If it stays like this, travelling will be hard for me, because someone always has to cook specially for me..." In the fall of 1917, Einstein's health had deteriorated; he was diagnosed with an ulcer (a problem that would plague him for the rest of his life), a liver ailment and jaundice. His cousin Elsa, whom he had known since childhood, took over his care and later became his second wife.