BY THE GLOBE ONLY.

Bring the given place to any part of the horizon, and the place at the opposite point of the horizon will be the antipodes.

EXAMPLES.

1. What place is that, the inhabitants of which are the antipodes to Pekin?

Answ. Near the mouth of the river Sauces, or Colerado, in Patagonia.

2. Where are the antipodes of London?

Answ. A little to the south of New Zealand, in longitude 180°, and 51° 31′ south latitude.

3. What place has its inhabitants antipodes to Cape Horn?

4. Where are the antipodes to Otaheite ?

5. Where are the antipodes to New Caledonia ?

6. Required the antipodes to Buenos Ayres.

7. Where are the antipodes to Falkland's Islands?

8. Required the antipodes to Madrid.

9. Where are the antipodes to the island of Juan Fernandez ?

10. Required the antipodes to the Friendly Isles. 11. Required the antipodes to the Philippine Islands. 12. Required the antipodes of Sierra Leone.

13. What people are the antipodes of the Pelew Islands? 14. A ship, sailing in the Pacific Ocean, found its latitude 51 S. and longitude 180°,-required the antipodes.

15. Suppose a line drawn from the Island of Jamaica

through the centre of the earth, in what part would this line meet the surface of the earth on the opposite side? 16. Required the antipodes to Bermudas.

Required the antipodes of the following longitudes and

To elevate the globe for the latitude of any place.

Elevate the pole, which is of the same name with the latitude, as many degrees as are equal to it, and bring the given place to the brass meridian.

When the globe is rectified for the latitude of any place, that place is in the zenith, and the wooden horizon represents the rational horizon of the place.

EXAMPLES.

1. Elevate the globe for Lisbon.

Answ. The latitude of Lisbon is 39° N.; hence the north pole must be raised 39° above the horizon,

2. Elevate the globe for the Cape of Good Hope. Answ. The Cape of Good Hope has 35° S. L.; hence the south pole must be raised 35° above the horizon.

PROBLEM XII.

To find the distance between two places, and the angle of

position.

BY THE GLOBE.

Case I.-When the distance is less than 90.

1. Lay the quadrant of altitude over both the places, so that the division marked O may be on one of the places; then the degree cut by the other place will shew the distance in degrees.

2. Multiply these degrees by 69+, and the product will be the distance in English miles.

The distance between two places, and the angle of posi tion, may also be found in the following manner.

1. Elevate the globe for one of the places, and, having brought it to the meridian, screw the quadrant of altitude over it; then move the quadrant till it come over the other place, and observe what degree of it this last place cuts.

2. Subtract this distance from 90, and you have the distance in degrees.

3. The quadrant of altitude, on the horizon, will shew the angle of position.

Case II-When the distance is greater than 90.

1. Find the antipodes of one of the places, and by Case I. measure the distance between this and the other place.

2. Subtract this distance from 180, and the remainder will be the whole distance required.

When the angle of position is required, this Case may be performed in the following manner.

1. Elevate the globe for the antipodes of one of the p'aces, and, having fixed the quadrant over the same, bring its edge over the other place, and observe the degree cut by it.

2. Add this to 90, and the sum will be the distance required.

3. The quadrant will show the position: only, W. must be read for E.; E. for W.; N. for S.; and S. for N.

Note. The angle of position, as found by the above rules, must not be confounded with the true bearing of one place from another, or that course which a ship must constantly steer in order to sail from one place to the other. This bearing cannot be found, but by calculation, as is shown by writers on navigation.

To find the distance of places on particular maps.

1. Take the distance of the two places with a pair of compasses.

2. Apply this distance to the side of the map, and you will have the distance in degrees; or apply it to the scale adapted to the map, and you will have the distance in miles.

A ready way to measure the distance of places, on a map, would be to draw the scale adapted to the map on a long slip of drawing paper, or parchment, extending it to a proper length, and marking the divisions close to the edge; then apply the edge of the paper to the places proposed, and it will show their distance.

Instead of multiplying by 694, to bring degrees into miles, they may be multiplied by 70, which will render the work easier.

Perhaps it would be of use if maps of Europe, Asia, &c. had one of the meridians graduated, on which distances might be measured with greater accuracy than on the sides. The latitudes of places would also be more easily found.

The bearing of places cannot be truly assigned by maps; but it may be observed, that the top of the map is the north, the right-hand the east, the bottom the south, and the left-hand the west.

K

EXAMPLES.

Required the distance, and angle of position, between London and the following places...

=

1. Copenhagen. Answ. 9°, 625 miles N. E. by E.

18. What is the length of Europe, from Lisbon, in the west, to the Uralian Mountains, in the east?

19. What is the distance between Constantinople and Pekin?

20. What is the breadth of N. America, from the Promontory of Alashka to Cape Charles, the extreme point of Labrador?

21. What is the breadth of S. America, from Cape Blanco, in Peru, to Cape St. Roque, in Brazil?

22. What is the breadth of Africa, from Cape Verd, in the west, to Cape Guardafui, in the east?

23. What is the distance between Cape Verd, in Africa, and Cape Roque, in America?

24. What is the distance between Panama, in America, and Manilla, one of the Philippine Islands?

25. What is the distance between the Island of Bombay and Nootka Sound?