"Cosmos: A Sketch of a Physical Description of the Universe" by Alexander Von Humboldt is a beautiful book which was highly influential at its time (the five volumes were published between 1845 and 1862), but which has became growingly inaccessible.
Intending to make Humboldt's masterpiece accessible for modern audiences, I have edited it in LaTeX starting from a OCR transcription of a scan of a very old English translation of the, book by Elise C. Otte. I illustrated the book with images in the public domain or with permissive licenses from Wikimedia Commons.
There is a lot of work to be done yet, but I'm releasing the first 26 chapters of the first volume here. I'm open to typo corrections and suggestions in general.