What nationality was the author of the book Horologium Oscillatorium?
Horologium Oscillatorium Horologium Oscillatorium: sive de motu pendulorum ad horologia aptato demonstrationes geometricae (Latin for "The Pendulum Clock: or geometrical demonstrations concerning the motion of pendula as applied to clocks"), often abbreviated Horologium Oscillatorium, is a book published by Christiaan Huygens in 1673; it is his major work on pendulums and horology. This work is regarded as one of the three most important work done in mechanics in the 17th century, the other two being Galileo Galilei’s "Discourses and Mathematical Demonstrations Relating to Two New Sciences" (1638) and Isaac Newton’s "Philosophiæ Naturalis Principia Mathematica" (1687).
Imogen Holst Imogen Clare Holst CBE (12 April 1907 – 9 March 1984) was an English composer, arranger, conductor, teacher and festival administrator. The only child of the composer Gustav Holst, she is particularly known for her educational work at Dartington Hall in the 1940s, and for her 20 years as joint artistic director of the Aldeburgh Festival. In addition to composing music, she wrote composer biographies, much educational material, and several books on the life and works of her father.