Sundial or Sun Clock is an instrument telling time by the
positions of the sun. Sundial may be the oldest of all scientific
instruments. Nowadays, sundial is not only an instrument,
but arts and crafts.
This book gives you lots of information about sundial ---
history, theory, geometry, mathematics, ...
Moreover, as all books I recommend, the photos are sharp,
clear, big, ... which are important for a reference book or
a collector's book.