The Guardian We all know the reader- annotated book of the present day, and we prefer not to think about it. It's a scruffy thing.
Somebody has used a yellow highlighter to mark significant passages - most of the text, it seems.
Perhaps it was the same person who scribbled some page numbers in ballpoint pen inside the back cover, with the odd word to show what subject the page numbers refer to, or who wrote a disparaging comment on the title page under the author's name. If it is a library book, there will be no way of telling who marked it up, but if it is private property, the owner's name will almost certainly be on the first blank page inside the cover. While it is not known who wrote the annotations, there appear to be three different hands, all dating from the early 17th century. The annotations have not been transcribed or studied in any detail, but it is clear that they were written by contemporary readers who were interested in recent developments in astronomy and were competent enough to comment in detail on Galileo's observations and findings. These annotations are important evidence for the impact of Galileo's ideas on his contemporaries and give a glimpse of the excited interest and polemical discussion which Galileo's work often provoked.