The fecond time returning, in his bill
An olive leaf he brings, pacific sign.

Pallas is the fame as Minerva, whofe functions, power, and character, we have before noticed. See page 147.

The planets are kept in a regular motion, and retained in an undeviating courfe, round the fun, by the power of this luminary's attraction, or gravity, combining with their own projectile force. By the latter expreffion is meant the force propelling bodies forward in a right line, which is the nature of all fimple motion. By the former is understood that power which withdraws them from their rectilineal courfes.

The fun

Is centre to the world, and other ftars,
By his attractive virtue and their own
Incited, dance about him various rounds:

Their wand'ring courfe now high, now low, then hid,
Progreffive, retrograde, or ftanding ftill.

MILTON.

This wonderful celeftial mechanism, which it is altogether foreign to a compendious tract to attempt explaining, was originally impreffed on the fyftem by its omnipotent CREATOR; to which primary impulfe it has with undeviating uniformity adhered, having never fuffered the fmaileft diminution of its elaftic virtue from the greatest distances of space, or intervals of time!!!

With what an awful world-revolving power
Were firft the unweildy PLANETS launch'd along
Th' illimitable void! Thus to remain,
Amid the flux of many thousand years,
That oft has fwept the toiling race of men
And all their labour'd monuments away,
Firm, unremitting, matchlefs in their courfe;
To the kind temper'd change of night and day,
And of the feafons ever ftealing round,

Minutely faithful: Such TH' ALL-PERFECT HAND!
That pois'd, impels, and rules the steady WHOLE.
THOMSON.

The Problems peculiar to the planets, though highly entertaining and ufeful, are but very few. Their folutions are as follow:

PROBLEM C.

To find the Place of a given Planet in the Ecliptic for any specified Time.

Inspect the ephemeris for the proposed month, and there, oppofite to the given day of the month, is the planet's place in the ecliptic, in the column appropriated to that planet. Thus, on November the 4th, 1797, it will be found that Saturn's place at noon was Cancer 11 deg. 54 min.-Ju- ' piter's, Aries 11 deg. 30 min.-Mars's, Libra 12 deg. 54 min.-Venus's, Sagittarius 22 deg. 40 min. Mercury's, Libra 25 deg. 33 min.-and the planet Herfchel's, Virgo 16 deg. 36 min.

In White's Ephemeris for the year 1797, page 32 is allotted to this planet, which is there ftyled the Georgian, or New Planet.

Having found thefe places on the globe, ftick the aftronomical characters of the different planets

он

on the refpective points of the ecliptic, and the globe will then be in a proper ftate to folve the Tucceeding problems, for the day mentioned in this problem. But if rigid accuracy be expected, the latitude of each planet muft be fought in the ephemeris, and the patches, which are their reprefentatives, fixed above or below the ecliptic, according as the latitude is either North or South, which is denoted in the ephemeris by the letter

n or s.

PROBLEM CI.

To find the Time when a given Planet rifes, culminates, or fets on a given Day of the Year, in a propofed Latitude.

Adjust the globe to the given latitude, and the fun's place at noon, on the propofed day. Find the planet's place, as directed in the laft problem, and turn the globe till its defignating mark comes in contact with the Eaftern part of the horizon; the index will then fhew the time of the planet's rifing: bring the faid mark to the brafs meridian, and the hour of its culminating will be seen: and, finally, turn the mark to the Western edge of the horizon, and the index will exhibit the time of the planet's fetting.

EXAMPLES.

On the 4th of November 1797, at London, lat. 51, the place of the planet Jupiter was Aries 11 deg. 30 min. Proceeding then, agreeably to the above precept, it will appear that he

rifes nearly a quarter before 4 o'clock in the afternoon, culminates at ten, and fets about half after 4 in the morning.

A fimilar operation repeated for each of the planets, will fhew fuch of them as are, or are not, in a pofition to become confpicuous on any night in the year.

Required the time when all the planets refpectively rife, culminate, and fet at London, on the commencement of each of the four seasons of the year, as stated in White's Ephemeris?

PROBLEM CII.

To find upon any given Day, in a propofed Latitude, what Planets are above the Horizon at Sun-Set,

Adjust the globe to the given latitude, and the fun's place at the noon of the given day. Bring the degree of the ecliptic then occupied by the fun, to the Western edge of the horizon, and ob. ferve which of the zodiacal conftellations are at that time above the horizon. Examine an ephemeris for the given day of the month, to difcover what planets are in any of thofe elevated figns: fuch, if the weather prove favourable, will be vifible on the evening of that day.

EXAMPLES.

On the 26th of November 1797, the fun's place The was 4 degrees 47 minutes of Sagittarius. globe being rectified, as above directed, for a given place, fuppofe London, and the fun's place

brought

ought to the Weftern femi-circle of the horizon, e figns of the zodiac then appearing above the prizon will be-the greateft part of Sagittarius, d the whole of Capricornus, Aquarius, Aries, ad Taurus. To thefe may be added two more, mely, Gemini and Cancer, for the planets which ay arife before midnight. Now, by examining e ephemeris, it will be found, that Capricornus, ries, and Cancer, were poffeffed at that period y Venus, Jupiter, and Saturn, which of courfe Fere vifible in the evening of that day.

N. B. The planets are not vifible till the fun s a certain number of degrees below the horizon. Mercury becomes confpicuous. when the fun has efcended 10 degrees-Venus, 5-Mars, 114upiter, 10-Saturn 11-and the New Planet, when the fun is 17 degrees below the horizon.

Required, what planets will be above the horizon on the following days, 1803, at fun-fet: the King's Birth-Day-the Anniverfaries of the Reftoration and Gunpowder-Plot-the Prince of Wales's Birth-Day-the Lord-Mayor's-Day,and the King's Coronation.

PROBLEM CIII.

To fhew by the Globe in what Pofition Venus is a Morning or Evening Star.

To perform this problem, rectify the globe for the latitude of the place and the fun's fituation in the ecliptic; feek the place of Venus by an ephemeris, and having found the corresponding fpot on the globe, append there fome defignating

mark,