It’s been a while since I posted a link to a Gutenberg Gem. I am subscribed to the Project Gutenberg feed, and scan it from time to time. Today’s Gem is volume 8 from the Encyclopædia Britannica: which includes topics from Destructor to Diameter. Interestingly, it includes an entry for “Dialing”, which is also known as gnomonics: the construction of sun dials. I was thinking about constructing a high accuracy sun dial just the other day. Anyway, lots of good stuff to check out.
Addendum: When I find something in Project Gutenberg which interests me, I somethings will just go search Google Books or the Internet Archive for other books on the same topic. Kind of bombed out on Google Books, but archive.org had the following:
Gnomonique by Bigourdan. In French, but it seems awesome.
Sundials: How to Know, Use and Make Them by Mayhall & Mayhall