This is the 8th book in Fred SawyerÕs Sciatherics series.
It includes translations of Hugo Michnik's early 20th century contributions to
the theory of sundials. These include the first full development of the equations
for seasonal hour lines on ancient sundials, the introduction of sidereal hour
lines for dials, and the invention of the bifilar sundial that indicates time
from the intersection of the shadows of two perpendicular wires raised to
different heights above the dial face. The book also includes 6 explanatory
articles on Michnik and his work, including the first biographical essay to
identify who Hugo Michnik was and to give details of his life.