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CHRONOLOGY 



another. Therefore, just as Fahrenheit chose 

 for his zero a mark thirty-two degrees below 

 freezing-point, in order to avoid negative measure- 

 ments, so the Julian period had its epoch fixed 

 to 1st January 4713 B.C., a point of time 

 antecedent to all other epochs, in order that its 

 era should be a convenient standard to which all 

 other chronological systems can be differentially 

 referred. Its length is 7980 Julian or Metonic 

 years, the product of 28 (Solar period), 19 (Lunar 

 period), and 15 (Indiction), and thus constitutes 

 a great cycle embracing and unifying three sub- 

 ordinate cycles which are constantly referred to ; 



because the year 4713 B.C. is the most recent date 

 when those important periods began exactly all 

 together. With the further development of techni- 

 cal chronology, and a more scientific treatment of 

 history and ethnology, we may look for a much 

 wider use and appreciation of the Julian period as 

 a cycle comprehending all really historic time, and 

 fulfilling certain astronomical conditions of the first 

 importance. When the year of the Julian period 

 is known, the corresponding date for any of the 

 subordinate cycles is easily found, and conversely. 

 We subjoin a table for the comparison of some 

 selected dates : 



EPOCHS AND LEADING EVENTS IN CHRONOLOGY REFERRED TO THE JULIAN PERIOD. 



The Julian period or cycle in its modern form 

 was proposed by Joseph Scaliger, but the Greeks 

 of Constantinople appear to be the authors of it. 

 Its exact epoch is noon of 1st January 4713 B.C. 

 for the meridian of Alexandria, which was chosen 

 as being that to which Ptolemy had referred the 

 era of Nabonassar already discussed. Scaliger has 

 the best right to the title of father of chronology, 

 often given to Eratosthenes. 



The astronomer Laplace in recent times proposed 

 another universal era not so practical in its bearing 

 on political chronology. He calculated that about 

 4000 years B.C. the major axis of the earth's orbit 

 coincided with the line of the equinoxes, and that 

 in 1250 A.D. they were at right angles. In the 

 latter year, therefore, he proposed to fix the univer- 

 sal epoch whence the whole world should reckon, 

 the vernal equinox, to be the first day of the first 

 year, when the solar perigee coincided with the 

 summer solstice. With Laplace's estimate may be 

 compared the dates of coincidence with the solar 

 perigee which are tabulated above. 



There are many other instances of astronomical 

 chronology overlapping and influencing political 

 chronology. Thus, by reckoning back we are able 

 to identify the time and place of some remarkable 

 eclipses, such as that of Thales (see in table 

 above), which caused the suspension of a battle 

 between the Medes and Persians. Another striking 

 verification was by that of Larissa, the Nimroud of 

 Mr Layard. Scottish history furnishes another 

 recent instance. We read that when King Haco 

 sailed from Bergen with his Norse fleet to punish 

 the king of Scotland, he put in at Ronaldsvoe in 

 Orkney, which was then subject to him, and that 

 there the sun appeared as a thin bright ring. Sir 

 David Brewster found by computation that there 



was an annular eclipse of the sun passing over 

 Orkney on 5th August 1263, about one o'clock. 

 Two months afterwards Haco was defeated at 

 Largs, and Alexander annexed the Hebrides to 

 Scotland. ' The ring at Ronaldsvoe was an evil 

 portent.' Such verifications in chronology are de- 

 pendent on the testimony of contemporary writers. 

 Other valuable information has been derived from 

 coins, medals, monuments, and inscriptions. 



To treat adequately many of the important rami- 

 fications of our subject is here impossible, and we 

 have therefore only passed under review the main 

 features of the science as a whole. One depart- 

 ment, however, of political or technical chron- 

 ology deserves special attention from its interest to 

 antiquaries and lawyers as well as to historians 

 viz. the method of assigning events to their respec- 

 tive years, or fixing their dates as it is called, 

 either by verifying in cases of doubt, or reconciling 

 and correcting in cases of discrepancy, inconsist- 

 ency, and contradiction. How, for example, can 

 the following dates be accounted for all printed in 

 the same month of the same year, 1705? In the 

 London Gazette of 13th February is given a trans- 

 lation of which there is an abridgment in the 

 Edinburgh Courant of the 19th, yet the original 

 passage is in the Amsterdam Gazette, dated 22d 

 February. 



The first cause of such discrepancies is the differ- 

 ence of styles (see CALENDAR), which occasions 

 seeming blunders of ten, eleven, or twelve days, 

 according to the century. As 170 years elapsed 

 before England adopted the new style, the chief 

 Roman Catholic countries being followed by Poland 

 (1586), Hungary (1587), Strasburg (1682), German 

 Protestant States (1700), and Tuscany (1749 or 

 1751), all in different years, there was ample 



