PART III. GEOGRAPHY AND ASTRONOMY. Mast. WH HAT I propofe at present is to confider the Science of Geography and Aftronomy; but particularly the firft. As to Aftronomy, I fhall content myfelf with juft giving you fome Idea of the Copernican Syltem, and leave you to make what farther Progrefs in it your felf or your Friends may think proper, as you advance farther in your Studies. But without a competent Knowledge of Geography, neither Hiftory can be understood, nor Politics; nor is it poffible to have juft Ideas either of Navigation or Commerce. Now the Science of Geography chiefly confifts in a Defcription of the Surface of the Terreftrial Globe, which is naturally compofed of two Parts, Land and Water, and is therefore called the Terraqueous Globe. Each of thefe Elements are fubdivided into various Parts, and are diftinguished by different Names. Sch. How are the feveral Parts of the Earth diftinguished? M. The Earth is divided into Continents, Iflands, Peninfulas, Ifthmus's and Promontories or Capes. A Continent is a large Portion of Land, containing feveral Countries united together, and Continent. not feparated by Seas: As Europe, Asia and Africa, form but one Continent in the Ea, and America another in the Welt. Ая Iland. Peninfula. An Island is a Portion of Land furrounded by Water, as Great Britain is. A Peninsula is a Portion of the Earth furrounded by Water, except on one Part where it is joined to fome other Land by a narrow Neck or Ifthmus. Africa is joined to Afia by the Ifthmus of Suez, and the Mrea is joined to Achaia by the Ifthmus of Corinth. Libmus. As An Ifthmus is that Neck of Land which joins two Countries together, as the Ifthmus of Darien joins North and South America, and the Ifthmus of Corinth, Achaia and the Morea. Cape or Pro- S. How are the Waters divided? M. The Waters are divided into Oceans, Seas, Straits, Bays or Gulphs, Lakes and Rivers. Oceans are the vaft Seas which divide one Part of the Earth from another, as the Atlantic Ocean which divides Europe and Africa from America, and the Pacific Ocean or South-Sea, which divides America from Afia. Seas. Seas are lefs Bodies of Water which divide one Country from another, as the Mediterranean which divides Europe from Africa, and the Baltic which divides Sweden from Germany. Bayor Gulph. A Bay or Gulph, is a Sea encompaffed with Land, except one Part whereby Ships enter it, as the Gulph of Mexico in America, and the Gulph of Finland in the Baltic. And the leffer Bays are frequently called Creeks or Sounds, as Plymouth-Sound. Creek or Sound. Strait. A Strait is a narrow Paffage into fome Sea, as the Strait of Gibraltar, and this is alfo fometimes' called a Sound, as the Strait by which we enter the Baltic Sea is. Lake. A Lake is properly a great Water furrounded by Land, which has no vifible Communication with any Sea, as the Cafpian Sea in Afia; but many other Waters which have a Communication with the Sea, are denominated Lakes alfo; as the Onega Lake in Ruffia, and the Lake of Nicaragua in America. River. A River is a Stream iffuing from fome Fountain, which after it has run a confiderable Courfe, difcharges itself ufually in fome Sea, as the Danube, which rifing in the Mountains of the Alps, after it has run a Courfe of many hundred Miles from Weft to Eaft, thro' great Part of of Germany, Hungary, and Turkey, discharges itself into the Euxine Sea by feveral Channels. Circumference of the Globe. S. Of what Dimenfions is the terreftrial Globe? M. The Circumference of the terreftrial Globe is 360 Degrees, every Degree being 60 Geographical Miles; fo that the whole Circuit is 21600 fuch Miles, and if the Diameter was a third Part of the Circumference, the Diameter would be 7200 Miles; but the Diameter is as 7 to 22, which makes it something Diameter. lefs than a third Part of the Circumference. If we reduce the Geographical Miles to English Miles, the Circumference of the Earth will be about 24000 Miles, and the Diameter 8000. S. What is the Earth founded upon ? Circles of the Globe. M. The terreftrial Globe refts upon nothing, but appears equally furrounded by the Heavens on every Side; for the better understanding whereof, it will be neceffary to obferve the feveral imaginary Circles defcribed on the artificial Globe, Plate 2. viz. 1. The Equator and the Circles parallel to it. 2. The firft Meridian and the rest of the meridional Lines. 3. The Zodiac, which includes the Ecliptic. 4. The Horizon. 5. The two Tropics. 5. The Artic and Antartic Circles. It is fuppofed alfo, that a Line paffes thro' the Center of the Globe, called its Axis, round which it moves every 24 Hours, the Ends of which Axis are called the Poles of the Earth, that in the North called the Artic or North Pole, from a Star in the Heavens oppofite to it, which forms part of the Constellation called the little Bear, and that in the South called the Antartic or South Pole, as diametrically oppofite to the other. S. Of what Ufe is that Circle denominated the Equator? Equator. M. By the Equator the Globe is divided into two equal Parts or Hemifpheres, and on this Circle are marked the Degrees of Longitude, from the first Meridian, either Eaft or Weft. The Parallel Circles are fo called from their running parallel to the Equator, of which there are nine in number, inclufive between the Equator and either Pole, ten Degrees diftant from each other, every Degree of Latitude being 60 Geographical Miles, and every ten Degrees 600 such Miles. Confequently, it is 5400 Miles from the Equator to either Pole, which is one quarter of the Circumference of the Globe. S. Of what Ufe is the first Meridian? M. The Meridian. M. The first Meridian is represented by the brazen Circle in which the Globe moves, dividing it into the Eaftern and Western Hemifpheres, on which Circle are marked the Degrees of Latitude, which are counted Northward from the Equator to the North Pole, and Southward from the Equator to the South Pole. Where the meridional Lines are 24 in Number, they are 15 Degrees or one Hour afunder; thofe who live under the meridian Line on the right Hand, that is, to the Eaftward of the first Meridian, have the Sun one Hour before us; and those who live under the meridional Line on the left Hand, that is, Weft of us, have the Sun an Hour after us; and this fhews what is meant by Eaftern and Western Longitude. And as Longitude is nothing more than the Diftance any Place is Eaft or Weft of the first Meridian, fo Latitude is the Diftance a Place is from the Equator North or South. If it be North of the Equator, it is called North Latitude, and if it be South of the Equator, it is called South Latitude. Longitude. Latitude. S. Where is the firft Meridian ufually placed? M. The firft Meridian in the old Maps was placed either at Teneriff, one of the Canary Isles, 17 Degrees Weft of London, or at Ferro, another of the Canary Ifles, 19 Degrees Weft of London. But every Nation almoft at this Day places the firft Meridian at their refpective capital Cities in their feveral Maps. In Moll's, which are the correcteft English Maps we have, London is made the firft Meridian at one End of the Map, and Ferro at the other; Ferro being 19 Degrees Weft of London, as has been obferved already. And in thefe Maps the upper End is always the North, the lower End the South; the right Hand Eaft, and the left Hand Weft, the Degrees of Longitude being marked at the Top and Bottom of each Map, and the Degrees of Latitude on the Sides of the Map. S. What is meant by the Zodiac? Zodiac. M. The Zodiac is that Circle which cuts the Equator obliquely, and is divided into twelve Signs, thro' which the Sun feems to pafs within the Space of 12 Months, each Sign containing 30 Degrees of Longitude. The Ecliptic is a Line paffing thro' the middle of the Zodiac, and fhews the Sun's or rather the Earth's Path or Orbit, in which it moves annually. S. Why do you fay the Earth's Orbit? Is it not the Sun that moves? M. No, M. No, but Geographers fpeak according to Appearances, the Appearance is the fame if the Earth moves from Weft to Eaft, as if the Sun moved from Eaft to Weft. Horizon. S. Which of the Circles is denominated the Horizon? M. The Horizon is the broad Circle in which the Globe ftands, dividing it into the upper and lower Hemispheres. The Place where any one ftands, is the Center of this Horizon and Hemifphere; the fenfible Horizon feems to touch the Surface of the Earth, and is the utmost Limits of our Sight, upon an extenfive Plain. The rational Horizon is fuppofed parallel to this, and to be extended to the Heavens. The Poles of our Horizon are two imaginary Zenith, NaPoints 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 oppofite 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, muft of course be under our Feet at 12 at Night; but fpeaking properly, no Part of the Earth can be faid to be uppermoft or lowermoft. All the Inhabitants of the Earth feem to have the Earth under their Feet, and the Heavens over their Heads, and Ships fail with their Bottoms oppofite to each other. S. Of what Ufe are the Circles denominated Tropics? ther the Earth proceeds North or South of the Tropics. Equator every Year. The Tropic of Cancer furrounds the Globe 23 Degrees North of the Equator, and the Tropic of Capricorn 23 South of the Equator. S. Where are the polar Circles placed? Polar M. The polar Circles are drawn 23 Degrees diftant from each Pole, and 66 diftant from the Circles. Equator. S. What are thofe Divifions of the Earth called Zones ? M. The Earth is divided into five Zones, viz. Zones. 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, Torrid Zone. and is fo denominated from the exceffive Heat of the Climate, the Sun paffing over it twice every Year. The |