Post Lot Text
First edition of Huygens's most important work, containing the first mathematical analysis of pendulum motion, a great achievement in the principles of dynamics. His theorems relating to the centrifugal force of circular motion assisted Newton in determining universal gravitation. The pendulum clock was Huygens's own invention; he constructed his first in 1657, following an idea of Galileo's about the isochronism of the pendulum. It meant a brilliant solution to the problems of keeping time aboard ship, which helped to determine longitude -- a question of the acutest concern to the greatest seafaring nation of the 17th century. Fine copy.