46. Find all those places of the earth to which the sun will be vertical on the 20th of May.

47 How do you find those two days of the year on which the sun will be vertical to any given place in the torrid zone?

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48. On what two days of the year will the sun be vertical to Bayamo, a town on the south coast of Cuba?

49. How do you find where the sun is vertical, the day and hour at any particular place being given?

50. On what two days of the year is the sun vertical at St. Christopher's island, in the West Indies?

51. How do you rectify the globe to the sun's declination, on a given day?

52. Rectify the globe to the sun's declination on the 1st of November. Name the circumstances.. 53. How do you illustrate by the globe, the variety in the length of the days and nights, and the change of seasons?

54. Required to show the comparative length of the day and night in all places on the earth, on the 4th of July; and also, to illustrate how the regular succession of day and night, and the change of seasons, are really caused by the diurnal and annual motions of the earth.

55. How do you rectify the globe for the latitude of a given place, and for the sun's place on a given day?

56. It is required to rectify the globe for the latitude of Washington City, and for the sun's place on the 21st of June.

57. How do you illustrate by the globe, the comparative length of the days and nights, in any particular place, at all times of the year?

58. It is required to show at one view the comparative length of the days and nights, at the tropic of Cancer, at all times of the year. Name the circumstances.

59. How do you find the rising and setting of the sun, and the length of the day and night at any place in the torrid or temperate zones ?

60. What time does the sun rise and set at Moscow on the 22d of December ?

61. How do you find the sun's declination and day of the month, the length of the day, at any particular place being given ?

62. On what two days of the year does the sun rise at 4 o'clock at Archangel?

63. How do you find those places in the torrid or temperate zones, when the longest day is of any given length, less than twenty-four hours?

64. In what latitude north is the longest day 16 hours? Name the most remarkable places.

65. Given the day of the month, at any particular place, not in the frigid zones, how do you find what other day is of the same length?

66. What day of the year is of the same length as the 20th of March?

67. How do you find the beginning, end, and duration of constant day and constant night at any place in the frigid zones?

68. What is the length of the longest day and longest night at the mouth of the Lena, a river in Asiatic Russia, which rises in the mountains northwest of lake Baikal, and falls into the Frozen Ocean in latitude 73 north, after a course of nearly 2000 miles ?

69. How do you find the number of days that the sun will rise and set alternately every twenty-four hours, at any place in the north or south frigid zones? 70. How many days of the year does the sun rise and set alternately every twenty-four hours, at Sabine island, in the Polar Sea?

71. How do you find in what degree of north latitude, on any day between the 20th of March and 21st of June, the sun begins to shine constantly without setting, and also in what latitude in the opposite hemisphere he begins to be totally absent?

72. In what latitude north does the sun begin to shine constantly without setting, and also in what latitude south does he begin to be totally absent, on the 25th of May?

73. Given any number of days not exceeding 187 north, or 178 in south latitude, how do you find the parallel of latitude in which the sun does not set during that time?

74. In what degree of latitude north does the sun continue above the horizon during 120 days of twenty-four hours each?

75. How do you find in what geographical climate any given place is situated?

76. In what climate is Havana ?

77. How do you find the breadths of the several climates, from the equator to the poles ?

78. What is the beginning, end, and breadth of the eleventh north climate; and what remarkable places are situated within it ?

79. How do you find the beginning, end, and duration of morning and evening twilight, at a given place, on a given day?

80. What is the duration of twilight at the tropic of Capricorn, on the 21st of June ?

81. How do you find the beginning, end, and duration of constant twilight at any place between the fortyninth degree of north or south latitude, and the north or south pole?

82., What is the duration of constant twilight at Archangel?

83. Having given the place and day of the month, how do you find the sun's meridian altitude?

84. What is the sun's meridian altitude at the north polar circle, on the 22d of December?

85. The sun's meridian altitude and day of the month being given, how do you find the latitude of the place of observation?

86. On the 20th of November, 1825, the sun's meridian altitude was observed to be 40° south of the observer, what was the latitude of the place? 87. How do you find the sun's azimuth and his altitude at any given place, the day and hour being given? 88. What is the sun's altitude, and his azimuth from the north, at New-Orleans, on the 21st of June, at 9 o'clock in the morning?

89. How do you find the sun's amplitude, at a given place, the day and hour being given? 90. On what point of the compass does the sun rise and set at Albany, on the 20th of March?

91. The sun's amplitude and day of the month being given, how do you find the latitude of the place of observation?

92. The sun's amplitude was observed to be 32° from the east towards the north, on the 21st of June; required the latitude of the place of observation.

93. How do you find the altitude of the sun at any place in the frigid zones, when it is midnight at a particular place in the torrid or temperate zones?

94. What is the sun's altitude at Sabine Island, when it is midnight at Bejapoor, a city in Hindoostan, on the 21st of June?

95. How do you find the sun's right ascension, &c. the day of the month at any place being given?

96. Required the sun's right ascension, &c. at Paris, on the 22d of December?

97. The day and hour at any place being given, to find all those places of the earth where the sun is rising, setting, noon, vertical, &c.

98. When it is eight o'clock in the afternoon a Rome, on the 25th of March, where is the sun rising, setting, noon, vertical, &c.?