There’s a common feature in old typography where the first word of a page is repeated at the end of the previous page, usually right-aligned on a line by itself. This book from 1759 shows this feature on nearly every page.
For example, page eleven could end with:
A sentence like this starts near the end of page eleven and
On page twelve you find:
then continues at the top of page twelve.
What do you call this feature?
After some digging, I found it is called a catchword. Read more about it here:
I always assumed this was to improve readability, as the reader could continue more seamlessly onto the following page, but it turns out it was also printed there to aid the bookbinder in ensuring that the pages were in the correct order.