The year 1787 was rendered further memorable by Laplace's announcement on the 19th of November (Memoirs, 1786), of the dependence of lunar acceleration upon the secular changes in the eccentricity of the earth's orbit.
Such were the Hindu nakshatras, a word originally signifying stars in general, but appropriated to designate certain small stellar groups marking the divisions of the lunar track.
The alternative view, advocated by Weber, that the lunar zodiac was primitively Chaldaean, rests on a very shadowy foundation.
The happy coincidence of a lunar eclipse gives us the 20th of September 331 as the exact day upon which the Macedonian army crossed the Tigris.
The os magnum of the second row articulating mainly with the lunar of the first, or with the cuneiform, but not with the scaphoid.
The stars had been numbered and named at an early date, and we possess tables of lunar longitudes and observations of the phases of Venus.
His method of estimating the relative lunar and solar distances is geometrically correct, though the instrumental means at his command rendered his data erroneous.
Here the " signs " and the " constellations " of the lunar zodiac form two essentially distinct systems. The ecliptic is divided into twenty-seven equal parts, called bhogas or arcs, of Boo' each.
From the same period also they have employed, in the adjustment of their solar and lunar years, a period of nineteen years, twelve of which are common, containing twelve lunations each, and the remaining seven intercalary, containing thirteen lunations.
The os magnum 1, lunar; sc, scaphoid; u, unciform; of the carpus articulates freely m, magnum; td, trapezoid; tm, with the scaphoid.
When Regard Is Had To The Sun'S Motion Alone, The Regulation Of The Year, And The Distribution Of The Days Into Months, May Be Effected Without Much Trouble; But The Difficulty Is Greatly Increased When It Is Sought To Reconcile Solar And Lunar Periods, Or To Make The Subdivisions Of The Year Depend On The Moon, And At The Same Time To Preserve The Correspondence Between The Whole Year And The Seasons.
Among the Arabian and later alchemists we find attempts made to collate compounds by specific properties, and it is to these writers that we are mainly indebted for such terms as "alkali," " sal," &c. The mineral acids, hydrochloric, nitric and sulphuric acids, and also aqua regia (a mixture of hydrochloric and nitric acids) were discovered, and the vitriols, alum, saltpetre, sal-ammoniac, ammonium carbonate, silver nitrate (lunar caustic) became better known.
Each planet had two houses - a solar and a lunar - distributed according to the order of their revolutions.
In the article Calendar (q.v.), that part of chronology is treated which relates to the measurement of time, and the principal methods are explained that have been employed, or are still in use, for adjusting the lunar months of the solar year, as well as the intercalations necessary for regulating the civil year according to the celestial motions.
There he continued his literary and scientific labours, enjoying congenial intercourse with such men as Matthew Boulton, James Keir, James Watt and Erasmus Darwin at the periodical dinners of the Lunar Society.
This is the Dionysian or Great Paschal Period, and is formed by the multiplication of the numbers 28 and 19, that is, of the solar and lunar cycles, into each other.
Thus the first moon of the year 1873 being the first of a new cycle, the first moon of every sixth year, reckoned backwards or forwards from that date, as 1868, 1863, &c., or 1877, 1882, &c., also begins a new lunar cycle of sixty moons.
At a printing-press established in Walther's house by Regiomontanus, Purbach's Theoricae planetarum novae was published in 1472 or 1473; a series of popular calendars issued from it, and in 1474 a volume of Ephemerides calculated by Regiomontanus for thirty-two years (1474-1506), in which the method of "lunar distances," for determining the longitude at sea, was recommended and explained.
The calendar was the Syro-Macedonian, a solar, as distinct from the primitive lunar, calendar, which Roman influence disseminated throughout Syria; it was practically a reproduction of the Julian calendar.
3 9) it is to be kept for seven days after the first, the first of which is to be "a sabbath," and the eighth "a sabbath" (possibly originally a lunar quarterday): branches of four trees are to be taken.
U, ulna; R, radius; c, cuneiform; 1, lunar; s, scaphoid; u, unciform; m, magnum; td, trapezoid; tm, trapezium.
Several cycles were formerly known in Europe; but most of them were invented for the purpose of adjusting the solar and lunar divisions of time, and were rather employed in the regulation of the calendar than as chronological eras.
And the Pleiades continued, within historical memory, to be the first asterism of the lunar zodiac. 2 Lenormant, Origines de l'Histoire, i.
The synodical revolution of the moon laid down the lines of the solar, its sidereal revolution those of the lunar zodiac. The first was a circlet of " full moons "; the second marked the diurnal stages of the lunar progress round the sky, from and back again to any selected star.
A ram frequently stamped on coins of Antiochus, with head reverted towards the moon and a star (the planet Mars), signified Aries to be the lunar house of Mars.
Excited to emulation and employing the more rapid wet-collodion process, he succeeded before long in obtaining exquisitely defined lunar pictures, which remained unsurpassed until the appearance of the Rutherfurd photographs in 1865.
The Passover was kept at the full moon of the lunar month Nisan, the first of the Jewish ecclesiastical year; the Paschal lambs were slain on the afternoon of the, 4th Nisan, and the Passover was eaten after sunset the same day - which, however, as the Jewish day began at sunset, was by their reckoning the early hours of the r 5th Nisan; the first fruits (of the barley harvest) were solemnly offered on the 16th.
Although it did not enter into the calendar of the Greeks, and was not introduced at Rome till after the reign of Theodosius, it has been employed from time immemorial in almost all eastern countries; and as it forms neither an aliquot part of the year nor of the lunar month, those who reject the Mosaic recital will be at a loss, as Delambre remarks, to assign it to an origin having much semblance of probability.
But in the course of a few years the accumulated difference between the solar year and twelve lunar months would become considerable, and have the effect of transporting the commencement of the year to a different season.
In 1872 Airy conceived the idea of treating the lunar theory in a new way, and at the age of seventy-one he embarked on the prodigious toil which this scheme entailed.
His treatise was remarkable, not only as offering a satisfactory explanation of the coincidence between the lunar periods of rotation and revolution, but as containing the first employment of his radical formula of mechanics, obtained by combining with the principle of d'Alembert that of virtual velocities.