Public domain photos

The image shows an old book with a black and white image of a man's face on it, which is the title page of the first edition of the German Patent No. 24. The paper is filled with text, giving us a glimpse into the contents of the book.

The image shows an old book with a black and white image of a man's face on it, which is the title page of the first edition of the German Patent No. 24. The paper is filled with text, giving us a glimpse into the contents of the book.Open in library