See also: List of stars in Horologium Horologium has one star brighter than apparent magnitude 4,  and 41 stars brighter than or equal to magnitude 6. In the midth century, English astronomer Francis Baily removed the designations of two— Epsilon and Theta Horologii —as he held they were too faint to warrant naming. Determining that the coordinates were wrong, he assigned the designation to another star. Kappa Horologii, too, was unable to be verified—although it most likely was the star HD —and the name fell out of use.
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Clues to the meaning of this celestial feature This constellation, Horologium Oscillatorium, was added by La Caille in to honor Christiaan Huygens who invented the first pendulum clock in , based on the pendulum introduced by Galileo Galilei. Horologium was also the term used for a sun-dial in ancient Roman times.
And in ancient Greece orologion was a name given to various instruments by means of which the ancients measured the time of the day and night. Derivatives: year, Yahrzeit the anniversary of the death of a relative, observed with mourning and the recitation of religious texts , horary, hour, horologe a device, such as a clock or sundial, or watch, used in telling time , horology the science of measuring time, the art of making timepieces , horoscope, these words from Greek hora, season.
The course of the seasons or hours is symbolically described by the dancing Horae, following each other in measured steps, they are an emblem of fleeting time.
They stand around the throne of Zeus, and their regular occupation is to open and shut the gates of Olympus Heaven , and yoke the steeds to the chariot of the Sun. In works of art the Horae were represented as blooming maidens, carrying the different products of the seasons.
The number of the Horae is different in the different writers, though the most ancient number seems to have been two, as at Athens; but afterwards their common number is three, and another group of twelve Horai or Horae were goddesses of the hours of the day. Janus might be adjacent Dorado and Horologium is also adjacent to Caelum , the celestial realm].
They oversaw the path of the sun-god Helios as he traveled across the sky, dividing the day into its portions. The ancient Greeks did not have hours of fixed length like we do today. Instead they divided the hours of daylight into twelve portions, identified by the position of the sun in the sky. Thus the length of the hour varied between the longer days of summer and shorter ones of winter. Hour hora is a Greek term compare ora , but it is pronounced in the same way in Latin.
The hour is the boundary of time, just as the word ora means a boundary like the shore of the sea, or the bank of a river, or the border of a garment. Watkins ] Oscillate literally refers to a steady back-and-forth motion, as that of a pendulum. The pendulum clock was originally called Horologium Oscillatorium, as was the name of this constellation before it was shortened to Horologium. In a passage in the Georgics, Virgil applies the word oscillum to a small mask of Bacchus hung from trees to move back and forth in the breeze.
They also examine the entrails of animals and predict the future from them. Watkins ] The horae were daughters of Zeus and Themis, goddesses of the seasons. These may have been the: Nymphs believed to be daughters of Zeus and Themis lived in a cave on the river Eridanus [Apollod.
Huygens placed cycloidal -shaped metal "cheeks" on either side of the pendulum string, to force the pendulum to move in a cycloidal path, to increase accuracy. 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"  is a book published by Christiaan Huygens in ; it is his major work on pendulums and horology. In the second part of the book, Huygens states three hypotheses on the motion of bodies. They are essentially the law of inertia and the law of composition of "motion". The fourth part of the book is concerned with the study of the center of oscillation. The derivations of propositions in this part is based on a single assumption: that the center of gravity of heavy objects cannot lift itself, which Huygens used as a virtual work principle. In the process, Huygens obtained solutions to dynamical problems such as the period of an oscillating pendulum as well as a compound pendulum , center of oscillation and its interchangeability with the pivot point, and the concept of moment of inertia.
This work inspired a generation of physicists and mathematicians, including Newton, Johanne Bernoulli, and Euler, for it reaches far beyond the working of pendulum clocks, and it still deserves a place in the historical presentation of the subject as presented today in elementary physics text books. For example, most of the intuitive ideas about centripetal forces are presented here in Part V. I am indebted on several points to the translation of Richard J. Blackwell, which I discovered only after most of my own translation; this admirable translation does not however include mathematical notes, apart from an introduction by H. This work also has the advantage of accessibility, and comes to you free of charge.
“THE HOROLOGIUM OSCILLATORIUM OF CHRISTIAN HUYGENS”