532 CHRON 
of time ; a chronologer.—-According to thefe chronologies, 
the prophecy of the Rabin, that the world fliould laft but 
fix thouland years, has been long difproved. Bronvn. 
CHRONO'LOGY, f \chromlogie, Fr. chronologia, Lat. 
from ^pov!^, time, and doftrine, or difcourfe.] A 
fcientihc method of afcertaining or computing time, from 
the commencement of fome given event, to the comple¬ 
tion or fulfilment of another; with the doftrine of dates, 
eras, epochs, See. coincident therewith. Like history, 
it opens through a great avenue to an expanded view of 
all human affairs, and connefts and illumines the raoft 
dark and diflant revolutions of the world. Yet it is to 
be lamented, that many and infuperable difficulties arife, 
in afcertaining the dates and periods of antiquity; con¬ 
cerning which much controverfy and irifterence of opi¬ 
nion has arifen. <! All nations,” fays fir Ifaac Newton, 
“ before they began to keep exaft records of time, feem to 
have been led away by the falfe pride of heightening their 
antiquity, and of aferibing their origin to fome divinity, 
or renowned prince, often known only in fable, and 
handed down by legendary tradition.” On this account, 
fir Ifaac found hiinfelf conftrained to deviate widely from 
the beaten path of former writers, in fixing the dates of 
fafts preceding the war between the Greeks and Perfians: 
“ yet fo affixing them,” fays he, “ as to make chronology 
fuit with the courfe of nature, with aftronomy, with sa¬ 
cred hiftory, and with itfelf.” 
Where, and about what time, chronology firft afiTumed 
the form of a regular fcience, may be eafily pointed out. 
Polybius is of opinion, that Ephorus of Cumae, the hifto- 
rian, was the firft who attempted it, under the form of an 
univerfal hiftory; and he flouriflied in the days of Philip 
of Macedon, about 350 years before Chriil; but nothing 
fatisfaftory upon this fubieft feems to have appeared till 
after the days of his fon Alexander; and fo late, indeed, 
as towards the clofe of the reign of Ptolemy Philadelphus, 
about the middle of the third century before Chrift: and 
the true reafon of it feems to be, that before the conquefts 
of Alexander, the Greeks had very fcanty materials for 
fuch a work; as their knowledge was confined to the 
tranfaftions of a narrow traft of country, and to the an¬ 
nals of a fhort period of time. For their travellers could 
not eafily import the hiltorical memoirs of the countries 
through which they palled ; becauie luch an undertaking 
would have required many advantages of which they were 
feldom mailers: fuch as, a thorough knowledge of the 
language of the country, a free accefs to all their princi¬ 
pal records, and a perfeverance in fuch application for a 
long feries of years. Even cruel and relentlefs wars, 
among their fatal calamities, have to fuch a work as this 
produced fome accidental good confequences, by the op¬ 
portunities they afford of obferving the fituation, nature, 
and improvements, of other nations; by which the pro- 
jjrefs of learning, and of many ufeful arts, has been the 
more eafily propagated into different countries. 
Strabo tells us, “ that the Greeks received great ad¬ 
vantages in their knowledge of geography, from the con- 
quells of Alexander; for by his means they became more 
perfeftly acquainted with the larger trails of Afia, and 
all the northern parts of Europe, to the river Iller;” and 
he might have mentioned too the whole extent of Egypt; 
fo that, at one and the fame time, they came to the full 
poffefiion of Babylon and Egypt, the two great fountains 
of ancient learning. “ The Romans,” fays he, “ in like 
manner, opened the fame light over the weftern parts of 
Europe, up to the river Elbe, which divided Germany 
into two parts; and tiiey went beyond the liter even to 
the Tyra ; and as for the countries round the lake Moeo- 
tis, and the fea-coaft to Colchis, they were undifeovered, 
till the days of Mithridates, lurnamed Eupator, king of 
Pontus; and the Parthian empire made Hyrcania, Bac- 
tria, and the Scythians that lived beyond them, to be bet¬ 
ter known,” We may therefore take for granted, that no 
general hiffory could be properly compofed, till the geo¬ 
graphy ot thefe countries was lufficientiy known, in order 
O L O G Y. 
to deferibe the ftrength of each particular kingdom, the 
number of its inhabitants, the progrefs of its armies, or 
the provinces that might be loft or acquired, in its quar¬ 
rels with other kingdoms. But whenever the accefs to 
All thele countries was laid open by the conquefts of A- 
lexander; when fo many new kingdoms were eftablifhed 
under the Macedonian government, into which the citi¬ 
zens of all the Greek ftates were freely admitted; when 
it extended the Greek tongue, as an univerfal language, 
over Afia and Egypt; it gave the moft favourable oppor¬ 
tunity to feveral eminent men to write the liiltories of 
different nations. Berofus compiled the hiltory of Chal¬ 
dea, from the records of Babylon; and Manetho that of 
Egypt, from the records of Memphis and of Thebes ; and 
the Arundelian Marbles gave a complete feries of the 
annals of Greece, from their earlielt times; all of which 
were compofed in that age, by cotemporary writers. And 
when we add to this, that the great library of Alexan¬ 
dria was firft formed under Ptolemy Philadelphus, into 
which the writings of all nations were collefted, we may 
fafely conclude from fo many united particulars, that it 
was then, and not before, that univerfal chronology be¬ 
came a fcience. 
The more attentively we confider the fituation of the 
world at this time, the more we fhall be convinced of the 
truth of this Affertion. For till there was a colleftion of 
proper materials brought together, fuch as the maou- 
feripts of all nations muff contain, it was impoffible to 
feparate the truth of hiftory from the rubbifh of fable; 
becaufe fafts are only to be canvaffed from a multitude 
of circumftances, which combine together to give light 
to each other, while the cotemporary hiftory of one coun¬ 
try correfponds to the cotemporary ftate of another. And 
as a library was neceflary to furnifh the materials for this 
purpofe, fo we find, that the firft great father of chrono¬ 
logy was Eratofthenes, the librarian of Alexandria, who 
had the command of all that treafury of learning. For 
the polfeffion of fuch a multitude of hiftorical memoirs 
both prompted and enabled him to determine the dates 
of many diftant fafts. And we are informed by Diony- 
fius of Halicarnaftus, that, in the execution of this work, 
he had laid down to himfejf certain chronological canons, 
which that great critic declares, he found to be accurate 
and uncorrupted, having examined them, in a treatife 
written purpofely upon that fubjeft, though, to the great 
misfortune of the learned world, it is now loft. 
The moft ancient data for the meafurement of time, 
appear to have been the returns of the feafons, and the 
generations of families. The fucceffion of Juno’s prieft- 
effes at Argos ferved Hellanicus for the regulation of his 
narrative ; while Ephorus reckoned time by generations. 
In Herodotus and Thucydides, there are no j-egular dates 
for the events recorded ; but Eratofthenes and Apollodo- 
rus digefted the events related by them, according to the 
fucceffion of the Olympiads, and of the Spartan kings. 
The chronology of the Latins is more uncertain : -the re¬ 
cords of the Romans were deftroyed by the Gauls; and 
Fabins Piftor, the moft ancient of their hiftorians, was 
obliged to borrow the chief part of his information from 
the Greeks. In other European nations the chronology 
is Hill more imperfeft, though of a later date : and even 
in modern times a confiderable degree of confufion and 
inaccuracy has arifen, from the want of attention among 
hiftorians to afeertain the dates and epochs with precifion. 
Hence is feen how neceflary a proper fyftem of chrono¬ 
logy mull be for the right underftanding of hiftory, and 
alio how difficult it is to eftablilh fuch a iyftem. For this 
purpofe, however, feveral learned men have fpent much 
time, particularly Julius Africanus, Eufebius of Caelarea, 
George Cyncelle, John of Antioch, Dennis, Petau, Cla- 
vius, Calvifius, Scaliger, Vieta, Newton, Uffier, Simfon, 
Brown, Mariham, Helvicus, Voffius, Strauchius, Blair, 
Playfair, and Walker. Their relearches for the accom- 
plilhment of fo valuable a fyftem, have been founded, 
ill. On agronomical obl’ervations, especially of the eclipfes 
