Frigid Zones. The two frigid Zones lie within the polar Circles, and are fo called from the exceffive Cold within thofe Circles. Zones. The Northern temperate Zone lies between Temperate the Tropic of Cancer, and the Artic Circle, and the Southern temperate Zone betwen 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 the Pole. equal to the Latitude of any Place, as the South of England lies in 50 Degrees of North Latitude, fo the North Pole muft of courfe be elevated 50 Degrees above the Horizon there, for which Reafon the Latitude of a Place, and the Elevation of the Pole, are used promifcuously to express the fame thing. S. Please to explain this by fome Inftances. M. When you rectify the Globe, and bring any Place to the Zenith, the Horizon muft of course be 90 Degrees diftant from that Place, either North or South. Suppose then the given Place lie in 50 Degrees of North Latitude, confequently the given Place must be 40 Degrees diftant from the North Pole, and the Pole must be 50 Degrees above the Horizon of that Place, to make up the 90 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, fuppofe you bring Petersburgh to the Zerith, which lies in 60 Degrees North Latitude, and confequently is within 30 Degrees of the Pole, then there muft 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 90 Degrees between the Zenith and Horizon on every Side to form the Hemisphere. S. Of what Ufe is the Hour Circle on the Globe? M. The brazen horary Circle fixed on every Hour Circle. Globe with an Index, fhews how many Hours, and confequently how many Degrees any Place is Eaft or Weft of another Place; for as every 15 Degrees Eaft or Weft is an Hour, fo every Hour is 15 Degrees 15 Degrees one Hour Eoft or Weft. The Quadrant of The Quadrant of Altitude is a pliant brafs Plate divided into 90 Degrees, one fourth of the Circumference of the Globe, by which the Dif tances of Places may be found, and many useful Problems refolved. S. How are the Inhabitants of the Earth diftinguished in regard to their refpective Situations? M. They are denominated either Periæci, Antæci, or Antipodes. Periaci. The Periæci are fituate under the fame Parallel, but oppofite Meridians: It is Midnight with one when it is Noon with the other, but the Length of their Days and their Scafons are the fame; these are found by the turning the horary Index 12 Hours, or turning the Globe half round. Antæci. The Antæci are fituate under the fame Meridian, but oppofite Parallels; these have the Seafons oppofite to ours, and the fame Length of Days; but when their Days are longeft, ours are shortcft. Thefe are found by numbering as many Degrees on the oppofite Side of the Equator as we are on this. Antipodes. The Antipodes lie under oppofite Meridians, and oppofite Parallels; thefe have different Seafons, and their Noon-day is our Midnight, and their longeft Day our fhorteft: Thefe 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 oppofite Side of the Equator as the given Place is on this. Different S. Are they diftinguifhed by any other Circumftances? M. The Inhabitants of the Earth are diftinguished by their different Shadows at Noon-day, and are denominated either Amphifcii, Afcii, Heterofcii, or Perifcii. Shadorus. Amphifcii. The Amphifcii inhabit the Torrid Zone, and have their Noon-day Shadows both North and 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 alfo called Afcii, because the Sun is vertical twice every Year at Noon-day, and then they have no Shadow. Afcii. Heterofcii. The Heterofcii, who inhabit the Temperate Zones, have their Shadows always one Way at Noon-day. In the Northern temperate Zone their Shadows are always North; and in the Southern temperate Zone, their Shadows are always South at Noon-day. The Perifcii. The Perifcii inhabit within the polar Circles, and have their Shadows every Way, the Sun being above their Horizon all the 24 Hours, feveral Months in the Year, viz. when it is on the fame Side of the Equator they were 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 fame Length. S. What are we to understand by Climates? M. Climates are Spaces on the Surface of the Climates. Globe, bounded by imaginary Circles parallel to the Equator, fo 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 refpectivePoles, between which laft, there is a Difference of an entire Month; the Sun appearing in the first one Month above the Horizon without fetting, in the fecond two Months, and fo 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 thefe Climates of an equal Breadth ? M. No, thofe near the Equator are much the broadeft; For Example, the firft 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 obferved in the following Table. Climates. To 24 Hours. Το 66 30 In the frigid Zone the Days increase by Months. A Day of one Month in 67 2 Months in 69 30 30 3 Months in 73 20 4 Months in 78 20 5 Months in 84 со 6 Months in 90 N. B. The End of one Climate is the Beginning of the next. At the firft Climate, which begins at the Equator, the Day is juft 12 Hours long at the Beginning of the Climate, and 12 Hours 30 Minutes at the End of it, viz. in 8 Degrees 25 Minutes of Latitude, where the fecond Climate begins. VOL. I. P S. I S. I obferve that every Degree of Latitude contains 60 Geographical Miles, please to inform me how many fuch Miles are contained in a Degree of Longitude? M. Every Degree of Longitude counted on the Equator is 60 Geographical Miles, but as the meridion al Lines approach nearer each other as you advance towards either Pole, confe quently the Number of Miles between thofe Lines must leffen in Proportion; for inftance, a Degree of Longitude in 52 Degrees of Latitude contains but 37 Miles, tho' it be full 60 Miles upon the Equator, and this will be found by measuring the Distances as well as by the following Table, which fhews how many Miles are contained in a Degree of Longitude in every Latitude. A TABLE of the Length of a Degree of Longitude in every |