bring the Patch to that Part of the Meridian (X) which is oppofite to the Sun; and fet the Hour-Index at 12 precifely.Thefe Things being done, you may darken the Room as foon as you pleafe, and then I'll put the Inftrument in Motion,

Euphrof. 'Tis done.

Cleon. Obferve the Earth equally divided into a light and dark Hemisphere, which reprefent Day and Night; as the Meridian paffes over the Middle Part of each; fo it fhews the Noon, or Mid-day to all Parts under it at the one, and Mid-night to all Parts under it in the other; among which you fee London (at X).—I'll now fet the Machine a-going:- Obferve the Earth revolving about its Axis from West to Eaft. *

Euphrof. I do, with Pleasure, behold it; and I obferve, that the Pofition of the Earth's Axis is fuch, as will bring London foon out of the dark Hemisphere into the enlightened one.

Cleon. It will fo; and I need not tell you, that that will be the Time from Mid-night to Sun-rifing, or the Length of Half the Night, at that Time. Obferve nicely the Time when the Patch begins to enter the Light.

Euphrof. I will.It will not be long I fee-It is now just come to the Point (0) or Circle of Illumination, and the Index is at 3h 47'.

Cleon. That is the Time of Sun-rifing on the 21st of June, and is the Morning of the Day.A Time very delightful in Summer, and is a favourite Theme with the

Poets,

As fome of our Readers may not have feen an Orrery, and others may not particularly remember the Phænomena of Day and Night which they faw reprefented in it, I have judged it neceffary to add a Diagram thereof (in Plate XXIV.) to affift the Understanding and Memory, in which, by a bare Inspection, all the Variety of the Alternations of Day and Night in the Summer, Equinoxial and Winter Seafons, is, it is prefumed, very eafy to be understood; and in a good Meafure, fuch a Print may fupply the Want of an Orrery, or other Inftrument for this Purpose.

N. B. In the Orreries which I make, the Earth is a Globe of 3 Inches Diameter, with all the Circles, Continents, and Oceans very diftinct.

Poets, who have all given us beautiful Defcriptions
thereof, particularly in the following Inftances.
Thus Virgil,

Now rofe the ruddy Morn from Tithon's Bed,
And with the Dawn of Day the Skies o'erfpread;
Nor long the Sun his daily Course withheld,
But added Colours to the World reveal'd.

Thus Garth,

Aurora, on Etefian Breezes borne,

With blushing Lips breathes out the fprightly Morn.
Each Flow'r in Dew their fhort-liv'd Empire weeps,
And Cynthia with her lov'd Endymion fleeps.

And Homer thus finely perfonates the Morn in the following Diftich:

Now rofy Morn afcends the Court of Jove,

Lifts up her Light, and opens Day above.

Alfo Mr. Thomfan's Defcription of Sun-rifing is too fine not to be taken Notice of.

Fierce flaming up the Heavens, the piercing Sun Melts into limpid Air the high-rais'd Clouds, And Morning Mifts, that hover'd round the Hills, In parti-colour'd Bands; till all unveil'd The Face of Nature fhines, from where Earth Far-ftretch'd around to meet the bending Spheres. Seafons, 74 Euphrof. Thefe are very beautiful and natural Descriptions, which, while you have been repeating, the Patch has got good Part of the Way towards the Meridian of Noon.

Cleon. I fee it is and thus the Sun rifes gradually higher and higher to the Inhabitants of London, till the Patch comes under the Meridian (at Z) where the Sun is at its greateft Meridian Height in the Tropic of Cancer (at r.) This makes the Noon of the Day thus admirably defcribed by the laft mentioned Poet.

'Tis raging Neon; and, vertical, the Sun
Darts on the Head direct his forceful Rays
O'er Heaven and Earth, far as the ranging Eye
Can fweep, a dazzling Deluge reigns; and all
From Pole to Pole is undiftinguifl'd blaze.
In vain the Sight, dejecte to the Ground,
Stoops for Relief; thence hot afcending Steams
And keen Reflection pain. Deep to the Root

Of Vegetation parch'd, the cleaving Fields
And flipp'ry Lawn an arid Hue difclofe,
Blaft Fancy's Blooms, and wither even the Soul.
Echo no more returns the chearful Sound

Of fharp'ning Scythe: The Mower finking, heaps
O'er him the humid Hay, with Flowers perfum'd,
And fearce a chirping Grafs-hopper is heard
Thro' the dumb Mead; diftrefsful Nature pants.
The very Streams look languid from afar ;
Or thro' th' unfhelter'd Glade, impatient, seem
To hurl into the Covert of the Grove.

Seafons, Page 81. Euphrof. It is now juft Noon in the Orrery, but far different from that you have now been defcribing.-Here every Thing is quiet and ferene; no fcorching Sun, no fweating, fainting Swains.-How inoffenfively, as well as pleafant, is the moft irkfome Part of the Day here represented by Art!

Cleon. Very true, Sifter; we here obferve the Hours of a Summer's Day pass without the Fatigue and Pain of enduring it.But Night comes ftealing upon us; the Patch approaches the Confines of Darkness, and the Sun as gradually declines.You will observe, it takes the fame Time in paffing over this Half of the enlightened Hemisphere as it did the other, viz. 8 Hours nearly; which, therefore, makes the longest Day 16 Hours at London.

Euphrof. I fee what you fay is Fact.-The Sun is now juft entering the Shades; and the Index points at viii. 13 ́. How confiftent is Art with Nature!

Cleon. Nature is the Contrivance of an infinitely wise Artist; if we poor Mechanics can fabricate an artificial World fo exactly, it is nothing wonderful to see fuch Beauty, Order, and Harmony in the Mundane Syftem.The Close of the Day is thus beautifully described by Homer:

As when the Morn, refulgent Lamp of Night,
O'er Heav'ns clear Azure Spreads her facred Light.
When not a Breath disturbs the deep Serene,
And not a Cloud o'ercafts the folemn Scene:
Around her Throne the vivid Planets roll,
And Stars unnumber'd gild the glowing Pole,

O'er the dark Trees a yellower Verdure shed,
And tip with Silver ev'ry Mountain's Head;
Then fhine the Vales, the Rocks in Prospect rife,
A Flood of Glory burfts from all the Skies;
The confcious Swains rejoicing in the Sight,
Eye the blue Vault, and bless the useful Light.
The Setting of the Sun is thus elegantly described by
Mr. Thomson.

Low walks the Sun, and broadens by Degrees
Just o'er the Verge of Day. The rifing Clouds
Affembled gay, a richly gorgeous Train,
In all their Pomp attend his fetting Throne :
Air, Earth, and Ocean fmile immense; and now,
As if the weary Chariot fought the Bow'rs
Of Amphitrite; and her tending Nymphs,
(So Grecian Fable fung) he dips his Orb;
Now half immers'd; and now a golden Curve
Gives one bright Glance, then total difappears.

This is followed by a Description of a Summer's Evening in thefe Words.

Confefs'd from yonder flow extinguish'd Clouds,
All Ether foft'ning, fober Evening takes
Her wonted Station in the middle Air;
A thoufand Shadows at her Beck. First this
She fends on Earth; then that of deeper Dye
Steals foft behind; and then a deeper ftill,
In Circle following Circle, gathers round,
To clofe the Face of Things. A fresher Gale
Begins to wave the Wood, and flir the Stream;
Sweeping with fhadowy Guft the Fields of Corn,
While the Quail clamours for his running Mate.
Wide o'er the thirsty Lawn as fwells the Breeze,
A whit'ning Flow'r of vegetable Down
Amufive floats.

Euphrof. These Descriptions are like the Poetry of Mr. Thomson, where every Thing is extraordinary. As you have fhewn me the Morning, Noon, and Night of the longest Day in the Orrery; let us now see the gradual Alterations which happen in regard thereto, while the Earth paffes on to the Winter Seafon.

VOL. I.

R

Cleon. That fhall be done, and is eafy by fetting the Machine in Motion.-See the Earth moving on towards Aries, and at the fame Time revolving about its Axis.And as it advances, you fee the Circle bounding Light and Darkness (bc) continually approaching towards the Poles (N, S,) and that London has its diurnal Path (ZO) in 'each Rotation, conftantly decreafing, while the nocturnal One (OX) is increasing as gradually, till at last they come to an Equality, when the Earth arrives at Aries.

Euphrof. All this I fee with great Pleasure,—and waiting a little, fhall foon find the Earth in Aries.-There feems now to be but a fmall Difference between the diurnal and nocturnal Tracts of the Patch.

Cleon. Very little; it is now fcarcely vifible.-The Earth has juft reached the Point, where I will cause it to move very flow, that you may better view the Appearances of the diurnal Motion.

Euphrof. Very good; I fee a perfect Equality of Night and Day, by Means of the Index and British Island; viz. 12 Hours each. At the fame Time, I oblerve the Reafon of this to be, that the Sun is in the Equinoctial at this Time; and, confequently, as all the Parts of the Earth have the diurnal Motion parallel thereto; and the Circle, bounding Light and Darknefs, paffes thro' the Poles; fo half that Motion must be performed in the enlightened Part, and the other Half in the dark, for every Part between the Equinoctial and the Poles; and, therefore, Day and Night must needs be equal now over all the Earth.

Cleon. You have a very juft Notion of the Matter ; and can account for all the Phænomena of Day and Night, I believe, in any Situation of the Earth, or Seafon of the Year. We will only, therefore, take a View of a Rotation or two of the Earth in the firft Point of Cancer; that is, in the Midst of the Winter Seafon.— Towards which you fee the Earth advances with an accelerated Motion in her Orbit, and confequently about her Axis. As Autumn paffes off, you fee Winter gradually coming on. The Days (with us) fhorten, and the Nights increafe;the N. Pole, by Degrees,

declines