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M. No, but Geographers speak according to Appearances, . the Appearance is the same if the Earth moves from West to East, as if the Sun moved from East to West.

S. Which of the Circles is denominated the Horizon? .

M. The Horizon is the broad Circle in which the Globe stands, dividing it into the upper andere

Horizon. lower Hemispheres. The Place where any one stands, is the Center of this Horizon and Hemisphere; the sensible Horizon seems to touch the Surface of the Earth, and is the utmost Limits of our Sight upon an extenfive Plain. The rational Horizon is supposed parallel to this, and to be extended to the Heavens.

The Poles of our Horizon are two imaginary Zenith, Na.
Points in the Heavens, called the Zenith and Na- dir.
dir; the Zenith being the vertical Point directly over our
Heads, and the Nadir that Point of the Heavens under our
Feet, diametrically opposite to the Zenith.'

S. Are any part of the Heavens under us?

M. As the Earth turns round upon its own Axis every 24 Hours, which makes Day and Night, that Part of the Heavens which was over our Heads at 12 at Noon, must of course be under our Feet at 12 at Night; but speaking properly, no Part of the Earth can be said to be uppermost or lowermost. All the Inhabitants of the Earth seem to have the Earth under their Feet, and the Heavens over their Heads, and Ships fail with their Bottoms opposite to each other.

S. Of what Use are the Circles denominated Tropics?

M. The Tropics shew how far the Sun or rather the Earth proceeds North or South of the

Tropics.

? Equator every Year. The Tropic of Cancer surrounds the Globe 23 i Degrees North of the Equator, and the Tropic of Capricorn 23 South of the Equator.

S. Where are the polar Circles placed ?

M. The polar Circles are drawn 23 Degrees distant from each Pole, and 66 { distant from the Equator.

S. What are those Divisions of the Earth called Zones ?
M. The Earth is divided into five Zones, viz.

20res.

2 The torrid Zone, the two frigid Zones, and the two temperate Zones; and are denominated Zones, because they encompass the Earth like a Girdle. The torrid Zone lies between the two Tropics,

between the two ropics, Torrid Zine.. and is so denominated from the excessive Heat of the Climate, the Sun palling over it twice every Year.

The

Polar Circles.

ones.

tbc Pcs

The two frigid Zones lie within the polar Comen Circles, and are so called from the excessive Cold within those Circles.

The Northern temperate Zone lies between Temperate Zones.

the Tropic of Cancer, and the Artic Circle, and

the Southern temperate Zone between the Tropic of Capricorn and the Antartic Circle.

S. What are we to understand by the Elevation of the Pole?

M. The Elevation of the Pole is the Height Elevation of of the Pole above the Horizon, and is always

equal to the Latitude of any Place, as the South of England lies in 50 Degrees of North Latitude, so the North Pole muft of course be elevated 50 Degrees above the Horizon there, for which Reason the Latitude of a Place, and the Elevation of the Pole, are used promiscuously to express the fame thing.

S. Please to explain this by some Instances.

M. When you rectify the Globe, and bring any Place to the Zenith, the Horizon must of course be 90 Degrees distant from that Place, either North or South. Suppose then the given Place lie in 50 Degrees of North Latitude, consequently the given Place must be 40 Degrees distant from the North Pole, and the Pole must be so Degrces above the Horizon of that Place, to make up the go Degrees on that Side. On the other hand, as the given Place lies 50 Degrees North of the Equator, your Horizon must extend to 40 Degrees of Southern Latitude, to make up the Complement of 90 Degrees on that Side. To explain this farther, suppose you bring Petersburgh to the Zenith, which lies in 60 Degrees North Latitude, and consequently is within 30 Degrees of the Pole, then there must be 60 Degrees between the Pole and the Horizon to make up the Complement of 90 Degrees. And on the other hand, the Horizon of Petersburgh will extend but to 30 Degrees of Southern Latitude, that making up the Complement of 90 Degrees on that Side, for there will always be go Degrees between the Zenith and Horizon 'on every Side to form the Hemisphere. S. Of what Use is the Hour Circle on the Globe?

The brazen horary Circle fixed on every

Globe with an Index, thews how many Hours, • and consequently how inany Degrees any Place is East or

15 Degrees West of another Place; for as every 15 Degrees one Hour Eaff East or West is an Hour, lo every Hour is 15 er 1'eli. Degrees.

The

Hour Cir

Quad

The Quadrant of Altitude is a pliant brass 9, Plate divided into 90 Degrees, one fourth of the Altitude. Circumference of the Globe, by which the Difftances of Places may be found, and many useful Problems reColved.

S. How are the Inhabitants of the Earth distinguished in regard to their respective Situations ?

M. They are denominated either Periæci, Antæci, or An

tipodes.

Perieci

The Periæci are situate under the same Parallel, but opposite Meridians : It is Midnight with " one when it is Noon with the other, but the Length of their Days and their Seasons are the same ; these are found by the turning the horary Index 12 Hours, or turning the Globe half round.

The Antæci are situate under the same Meridian, but opposite Parallels; these have the Sea

Anteci. fons opposite to ours, and the same Length of Days; but when their Days are longest, ours are shortest. These are found by numbering as many Degrees on the opposite Side of the Equator as we are on this.

The Antipodes lie under opposite Meridians, and opposite Parallels; these have different Seafons, and their Noon-day is our Midnight, and their longest Day our shortest: These are found by turning the horary Index 12 Hours from the given Place, or turning the Globe half round, and then counting as many Degrees on the opposite Side of the Equator, as the given Place is on this.

S. Are they distinguished by any other Circumstances ?
M. The Inhabitants of the Earth are distin-

the Lann are antin. Different

D; guished by their different Shadows at Noon-day, Shadows. and are denominated either Amphiscii, Ascii, Hetéroscii, or Periscii.

The Amphiscii inhabit the Torrid Zone, and have their Noon-day Shadows both North and

Amphifcii. South: When the Sun is South of them, then their Shadows are North, and when the Sun is North of them their Shadows are South ; these are also called Afcii, because the Sun

Ascii.

: is vertical twice every Year at Noon-day, and then they have no Shadow. : The Heteroscii, who inhabit the Temperate Zones, have their Shadows always one Way at

Heteroseii. Noon-day. In the Northern temperate Zone their Shadows are always North; and in the Southern temperate Zone, their Shadow's are always South at Noon-day.

The

quithafe denoperifci. inhabit the

The Periscii inhabit within the polar Circles, Periscii.

and have their Shadows every Way, the Sun being above their Horizon all the 24 Hours, several Months in the Year, viz. when it is on the same side of the Equator they are of; and if there were any Inhabitants at either of the Poles, they would have but one Day of 6 Months, and one Night of the same Length. Š. What are we to understand by Climates?

M. Climates are Spaces on the Surface of the andres. Globe, bounded by imaginary Circles parallel to the Equator, so broad that the Length of the Day in one exceeds that of another half an Hour, of which there are 60 in Number, viz. 24 from the Equator to each of the Polar Circles, and 6 from either of the Polar Circles to the respective Poles, between which last, there is a Difference of an entire Month ; the Sun appearing in the first one Month above the Horizon without setting, in the second two Months, and so on to the Pole, where there is a Day of 6 Months, and the

Nights proportionable, when the Sun is on the oppofite Side · of the Equator.

S. Are these Climates of an equa IBreadth ?

M. No, those near the Equator are much the broadeft ; For Example, the first Climate next the Equator is 8 Degrees odd Minutes in Breadth, whereas the 11th Climate is little more than 2 Degrees broad, as may be observed in the fol

bowie than 2 De Breadth, whe next the Emuch the bro

Climates,

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66

23

66
To 24 Hours.

To 66
In the frigid Zone the Days encrease by Months.

A Day of one Month in 67

2 Months in 69
3 Months in 73
4 Months in 78.
5 Months in 84
6 Months in 90

00 N. B. The End of one' Climate is the Beginning of the next. At the first Climate, which begins at the Equator, the Day is just 12 Hours long at the Beginning of the Cliinate, and 12 Hours 30 Minutes at the End of it, viz. in 8 Degrees 25 Minutes of Latitude, where the second Climate begins. VOL. I,

S. I

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