SEAS.

OF SEAS (properly fo call'd) there are but of the Seas. few; viz. The Mediterranean Sea, included between Europe on the North, and Barbary and Egypt on the South, and Part of Afia on the Eaft and North-Eaft. (2.) The Baltic Sea, inclofed with Sweden on the West, Lapland on the North, Part of Poland on the East, and Part of Germany on the South. (3.) The German Sea, inclofed with Great Britain on the Weft, and Scandinavia on the East. (4.) The Irish Sea, or rather Streights, or Chanel, between Ireland and Great Britain. (5.) The Euxine Sea, inclosed with Part of Europe on the North and West, and Part of Afia on the South and Eaft. (6.) The Cafpian Sea, or rather the greatest Lake in the World, as being entirely furrounded with Land on the Continent of Afia. All other Seas befides these are but Parts of the Oceans.

As for GULPHS, STREIGHTS, LAKES, RIVERS and BAYS, they are fo numerous, and of fo little Importance in a bare Rehearsal of their Names, that the Reader can expect to find a diftinct Account of them only in larger Treatifes on this Subject.

Of

Of CHRONOLOGY, or
the DOCTRINE of TIME.

HRONOLOGY is a Science Chronology de-
which has for its Subject the Do-fined.
Etrine of Time. Or, it is a Dif
cipline which is converfant about
the Nature, Properties, Parts,
and Ufe of Time, in a Civil Senfe.

THE Nature of Time is of a Phyfical Confi- The Nature of
deration; and therefore Time is defined to be the Time defined.
Duration of Things; and the Parts of Time the
Intervals of Succeffion of Phanomena; and the

Idea we have thereof confifts in the Order of The Idea fucceffive Perceptions. This Definition agrees to thereof. Time abfolutely confider'd; but Time in a relative Of Abfolute Senfe, is that which is measur'd or estimated by and Relative certain Motions, either equal, as Clocks, Watches, &c. or unequal, as of the Sun or other Heavenly Bodies; and this is otherwife call'd apparent or vulgar Time.

Time.

THE Parts of Time in use among us are Mi- of the Parts nutes, Hours, Days, Weeks, Months, Years, Ages, of Time. Cycles, and Periods. A View and Explanation

of the Nature and Ufes of these make the first Part of this curious and excellent Science of Chronology.

IT appears to me to be a prepofterous Me- The true Method of treating the Doctrine of Time, to begin thod of treat with Minutes, Hours, &c. and not (as the Na- ing of Time. ture of the Thing requires) with that Measure of

Ꮓ

Time,

A Year defin'd.

Of the Solar

Time, which is the Original and Standard, on which the reft depend; or the Whole, of which the others are but Parts and Subdivifions.

THIS Original, Standard, or Integral Measure of Time, then, is that we call a Year. A Year is the Space or Part of Time or Duration meafured by one entire Revolution of fome celestial Body in its Orb, viz. the Sun or Moon.

THAT which is measured out by the RevoTropical Year. lution of the Sun in the Ecliptic, is call'd the Solar Year; and this is properly the Natural or Tropical Year, which contains 365 Days, 5 Hours,, 48'. and 57".

Of the Solar
Sydereal Year.

Of the Lunar
Year.

Years Aftrono

BUT the Space of Time in which the Sun departing from any fixed Star, comes to it again, is call'd the Sydereal Year, which contains 365 D. 6 H. 9'. 14".

THE Lunar Year, is the Space of Time, in which the Moon performs 12 compleat Revolutions about the Earth, call'd Lunations; and contains 354 D. 8 H. 48'. 38".

YEARS are diftributed into Aftronomical and mical or Civil. Civil; the Aftronomical Year is that which results from, or depends on the Principles of Aftronomy: Such are thofe above defcribed: For the Tropical Year depends on one of the Cardinal Points, viz. the Equinox or Solstice; and the Sydereal Year on a fixed Star; and both on Aftronomical Obfervation and Calculation.

The Civil
Year, what.
Common, and
Biffextile or
Leap-Year.

THE Civil Year is that in common Ufe among the feveral Nations of the World; it is either Solar or Lunar. The Civil Sclar Year is again either Common or Biffextile. The Common Year is reckon❜d to contain only 365 Days, the odd Hours and Minutes being here neglected. The Biffextile Year, otherwife call'd Leap-Year, confifteth of 366 Days; the Day over and above

the

the Common Year, being call'd the Intercalary or

Biffextile Day.

THIS Intercalation of a Biffextile Day was firft The Original appointed by Julius Cæfar, to be made every tile or Leapof the Biffexfourth Year, to the end the Civil Year might rear. keep pace with the Tropical Year. For the fix Hours, whereby the latter exceeded the former, in four Years make a whole Day; which therefore was then added to the 23d Day of February, which was the Sixth of the Čalends of March in the Roman Calendar. In this Year therefore they reckon'd that fixth Day twice (in Latin, Bis fextus Dies) and thence came the Name Biffextile for Leap-Year. But in our Almanacks we add that Intercalary Day at the End of the faid Month, every fourth Year.

THE Civil Lunar Year is Common or Emboli- Of the Civil mic. The Common Lunar Year confifts of 12 Lunar Year. Lunations, which are finifh'd in 354 Days, at the End of which the Year begins again. The

Embolimic Year was that wherein a Month was Common and intercalated, to adjust the Lunar to the Solar Embolimic. Year. This Intercalation or Embolism was used

by the Jews, who went by the Lunar Motions in their Accounts.

THE Romans alfo at first used this Embolimic of the Origi Lunar Year, which was fettled by Romulus their nal of the Jufirft King, and confifted only of ten Months, lian Year, or Old Style. or 304 Days; and thus coming fhort of the true Lunar Year by 50 Days, and of the Solar Year by 61, this Year became vague and unfix'd: Which Numa Pompilius, the fecond King, obferving, added two other Months, January and February, and thereby made the Year confift of 12 Months, or 355 Days. But this Improvement not being fufficient to adequate the Year to the Motion of the Sun or Moon, and keep the Seafons even and steady; Julius Cæfar instituted the Z 2 Civil