Jupiter's path, when delineated, will be south of the ecliptic in the order A, B, C, D, E, F, G, H. Thus, he will appear at A on the 1st of January, at B on the 1st of March, at C on the first of April, at D on the 1st of May, at E on the 1st of June, at F on the 7th of July, at G on the 25th of August, and at H on the 25th of October. On the 25th of August, when Jupiter appears at G, he will be a little to the right hand of the star marked in Gemini; when he arrives at H, which will happen on the 25th of October, he will apparently return again to G, a small matter above his former path, where he will be situated on the 25th of December. Jupiter will not be visible during the whole of his apparent progress from A to H, being too near to the sun during the months of May and June.

In the same manner the places and situations of the stars may be delineated; thus, Aldebaran, the principal star in the Hyades, will be found by the Globe, (or a proper table) to be situated in 7° of II and in 51° of south latitude; Betelguese in Orion's right shoulder, in about 26° of II and in 16° of south latitude, and its place may be laid down on a map by extending the line of its longitude as from L, till it meets a straight line passing through 16, 16, on the sides of the map. In the same manner any other star's situation may be described; thus, the Hyades will appear at Q, the Pleiades at P, &c. and Bellatrix, &c. as in the figure.

The constellation Orion, here described, is a very conspicuous object in the heavens in the months of January and February, about 9 or 10 o'clock in the evening, and will be an excellent guide for determining the positions of several other constellations, particularly Canis Major, Canis Minor, Auriga, &c.

PART IV.

CONTAINING,

1. A promiscuous Collection of Examples exercising the Problems on the Globes.-2. A collection of Questions, with References to the Pages where the Answers will be found; designed as an Assistant to the Tutor in the examination of the Scholar 3. A Table of the Latitudes and Longitudes of the Principal Places in the World.

CHAPTER I.

A promiscuous Collection of Examples exercising the Problems on the Globes,

1. WHAT day of the year is of the same length as the 14th of August?

2. How many miles make a degree of longitude in the latitude of Lisbon?

3. At what hour is the sun due east at London on the 5th of May?

4. There is a place in the parallel of 31 deg. of north latitude, which is 31 deg. distant from London; what place is it?

5. If the sun's meridian altitude at London be 30 deg. what day of the month, and what month is it?

6. On what month and day is the sun's meridian altitude at Paris equal to the latitude of Paris?

7. When Draconis is vertical to the inhabitants of London at ten o'clock at night, what day of the month, and what month is it?

8. What is the equation of time dependent on the obliquity of the ecliptic on the 14th of July?

9. I observed the pointers in the Great Bear, on the meridian of London, at eleven o'clock at night; in what month and on what night did this happen?

10. On what day of the month, and in what month, will the shadow of a cane, placed perpendicular to the horizon of London, at ten o'clock in the morning, be exactly equal in length to the cane?

11. The earth goes round the sun in 365 days 6 hours nearly; how many degrees does it move in one day, at a medium? Or, what is the daily apparent mean motion of the sun?

12. The moon goes once round her orbit, from the first point of the sign Aries to the same again, in 27 days 7 hours 43 minutes 5 seconds; what is her mean motion in one day?

13. The moon turns round her axis from the sun to the sun again, in 29 days 12 hours 44 minutes 3 seconds, which is exactly the time that she takes to go round her orbit from new moon to new moon; at what rate per hour are the inhabitants (if any) of her equatorial parts carried per hour by this rotation? The moon's diameter being 2144 miles.

14. How many degrees does the motion of the moon exceed the apparent motion of the sun in 24 hours?

15. The day of the month being given, it is required to find the moon's longitude when she is eight days old. 16. Travelling in an unknown latitude I found, by chance, an old horizontal dial; the hour-lines of which were so defaced by time that I could only discover those of IV and V, and found their distance to be exactly 21 degrees; for what latitude was the dial made?

17. Required the duration of twilight at the south pole.

18. How far must an inhabitant of London travel southward to lose sight of Aldebaran ?

19. What is the elevation of the north polar star above the horizon of Calcutta?

20. Lord Nelson beat the French fleet near latitude 31 deg. 11 min. north, longitude 30 deg. 22 min. east ; point out the place on the globe.

21. What is the sun's altitude at three o'clock in the afternoon at Philadelphia on the 7th of May?

22. What is the length of the day at London on the 26th of July, and how many degrees must the sun's de clination be diminished to make the day an hour shorter?

23. At what hour does the sun first make his appearance at Petersburg on the 4th of June?

24. At what rate per hour are the inhabitants of Botany Bay carried from west to east by the rotation of the earth on its axis?

25. When Arcturus is 30 deg. above the horizon of London, and eastward of the meridian, on the 5th of November, what o'clock is it?

26. Describe an horizontal dial for the latitude of Washington.

27. Describe a vertical dial facing the south, for the latitude of Edinburgh.

28. What is the moon's greatest altitude to the inhabitants of Dublin?

29. What is the sun's greatest meridian altitude at the southern extremity of Patagonia ?

30. At what hour at London, on the 15th of August, will the Pleiades be on the meridian of Philadel phia?

31. If a comet, whose longitude was 4 signs 5 deg. and latitude 44 deg. north, appeared in Ursa Major, in what part of the constellation was it?

32. On what point of the compass does the sun set at Madrid when constant twilight begins at London?

33. What is the difference between the duration of twilight at Petersburg and Calcutta, on the first of February?

34. How much longer is the tenth of December at Madras than at Archangel?

35. How much longer is the 5th of May at Archangel than at Madras?

36. When it is two o'clock in the afternoon at London, on the 15th of February, to what place is the sun rising and setting, and where is it noon?

37. Does the sun shine over the north or south pole on the 17th of April, and how far?

38. At what hour on the 18th of April will the sun's altitude and azimuth, from the east towards the south,. be 40 deg. at London?