EXAMPLES.

When will the ftar in the tip of the Tail of Urfa Major be on the meridian at midnight?-Anf. ' pril 16.

Required when the following stars will be upon he meridian at midnight.

B, in the Shoulder of Auriga-3, in the Tail f Cetus-ß, in Aries-y, in Orion-y, in the oot of Lepus-a, Regulus, or Cor Leonis, in co-8, in the North Horn of Taurus-, in agittarius-ß, in Pifcis Auft-B, in Xiphias-6, n Pifcis Volans-the North Star in Crufero.

PROBLEM LXXVII.

In a given Latitude, Day of the Month, and Hour of the Night, to find the Altitude and Azimuth of a propofed Star. See Defin. 8, 9, pages 248, 249.

Rectify the globe for the given latitude, and day of the month at noon; revolve the globe till the index points to the propofed hour; fix the quadrant of altitude on the zenith, and move it to the given ftar, whofe azimuth will then appear on the horizon, and its altitude on the edge of the quadrant.

What are

EXAMPLES.

the altitude and azimuth of Cor Leonis, at London, on May 11, at eleven o'clock

at night?

Anf

Arf. Altitude about 2-°; azimuth about -6° from the South towards the Weft, or nearly W. by S.

Required the altitudes and azimuth of the fol lowing stars on the annexed days and hours of the night at London:

, near the Neck of Andromeda, January 30, at five o'clock in the evening, in the Mouth of Pegatos, February 3, at fx-, in Bootey March 24, at feven-, in the Arm of Virg April 8, at eight-, in the Head of Leo, May at nine-, in Cancer, near the Head of Hedra, June 17, at feven-, in the Tail of Aquila, J £1, at ten-s, in the Back of the Goat in Aurig, Augat 1, at eleven- in the Break of Cetry September 18, at midnight—, in the Fore Leg of Lépcs, October 13, at one-8, in the Foot of Canis Major, November 14, at two-, in the Tail of UHa Major, three o'clock in the morning.

PROBLEM

LXXVIII.

From the obferved Altitude of a Star, to find the Hear of the Night in a given Day of the Maxi, and in a broren Latitude.

Rectify the globe for the given latitude and dar of the month at noon; then revolve the globe t the ftar interiects the edge of the quadrant in the propofed degree of altitude, and the index will exhibit the hour of the night.

EXAMPLES.

What is the hour of the night at London, on the 11th of May, when the altitude of Cor Leons is 27 degrees?-Anf. Eleven o'clock at night.

N. B.

N. B. This Problem being the direct converse of the laft, the pupil may make ufe of the stars here enumerated, having previously obtained their efpective altitudes on the days and hours menioned, in the manner of the above example.

PROBLEM LXXIX.

From the obferved Hour and Minute of a Star's rifing or fetting on a given Day, to find the Latitude of the Place.

Rectify the globe to the given day at noon, and turn it about till the index points precifely to the given time, when, keeping it fteady, let the meridian be moved up and down in the notches of the horizon till the given ftar begins to emerge above it; then will the degrees of the meridian interfected by the North part of the horizon, fhew the elevation of the Pole, and confequently the latitude of the place. See Art. 25, page 23.

EXAMPLES.

Suppofe on the 11th of May, at four o'clock in the morning, the brightest star in Caput Medufæ were feen rifing, what would be the latitude? -Anf. About 28 degrees North.

Required the latitude of the places where the following ftars rife at the hours and on the days. annexed to them:

Rigel, in Orion, January 21, feven in the evening-Arcturus, in Boötes, February 16, at eighty, in Draco, March 14, at nine-a, in Lyra, April 11, at ten-a, in the wing of Pegafus, May

14, at eleven-, in the Heel of Andromeda, June 15, at midnight-a, in Orion, July 22, at one in the morning-a, in Urfa Major, Auguft 21, at two-Cor Leonis, September 23, at three-, in Serpens, October 20, at four-e, in Crufero, November 12, at five-Cor Scorpionis, December 20, at fix o'clock in the morning.

PROBLEM LXXX.

From an Obfervation of two known Stars being upr the fame Azimuth in a given Latitude, to find the Hour of the Night.

Rectify the globe for the latitude and fun's place at noon of the given day; turn the globe and quadrant till the edge of the latter lies precifely over both the given ftars; then will the index point to the hour of the night.

EXAMPLES.

Suppofe on the 11th of May, at London, lat. 51, Vega in Lyra, and Alcair in Aquila, were obferved to have the fame azimuth, what would be the hour?-Ans. About half past two in the morning.

Required the time of night at London when the following ftars have the fame azimuth on the annexed days?

Algol, in Caput Medufæ, and Aldebaran, in Taurus, January 3-6, in Pollux, and Cor Hydra, February 6-Cor Caroli, and Arcturus, March 21 - in the Shoulder of Boötes, and a, in Corona Borealis,

Borealis, April 9-a, in Cygnus, and a in Pegafus, May 12-, in the Head of Cepheus, and a, in the Horn of Aries, June 22-y, in the Arm of Perfeus, and B, in the North Horn of Taurus, July 7,-, in the Goat in Auriga, and Procyon, in Canis Minor, August 20-a, Betelgueze, in Orion, and Sirius in Canis Major, September 4-a, in the Arm of Cepheus, and y, in the Heel of Andromeda, October 16-a, Cor Leonis, and in Crater, November 15-a, in the Head of Caftor, and a, Cor Hydra, December 13.

PROBLEM LXXXI.

From an Obfervation of two known Stars having the fame Altitude on a given Day, to find the Hour of the Night.

Rectify the globe to the given latitude and day of the month at noon; revolve the globe until the fame degree of the quadrant of altitude correfponds with each of the propofed stars, then will the index fhew the hour of the night.

EXAMPLES.

Suppofe on the 11th of May, at London, lat. 514. the bright ftar (a) in the wing of Pegafus, and that in the head of Andromeda, were obferved to have an equal altitude, what would be the hour? -Anf. About & paft 2 in the morning.

Required the time of the night at London when the fubjoined ftars have the fame altitude on the annexed days:

U 2

a, in