Also, let me add that I could not link to the paper at the Einstein Archives for reasons explained in this thread. You can still find his papers all over the web, but this important and previously open archive appears to be converting to subscription access.
bsky.app/profile/mcne...
P.S. Princeton University Press (@princetonupress.bsky.social) hosts an online archive of Einstein's papers. In the past, the papers could be accessed by anyone. But it looks like they may be converting to paid access? I'm not sure.
einsteinpapers.press.princeton.edu/einstein-dat...
