The combination of the two bearings, and the latitudes of the hill of Camoa and Havanna, gives the former E. of the city of Havanna 11′ 05′′,2=44′′,3 in time. Observations made on a lunar eclipse, on the 14th Novr. 1807. Observation of apparent lunar distances, observed with the circle of reflection, at the plantation.-The distances in the following table are the result of 4 series of direct and inverse ob January 11th, 1808. Occultation of by the moon. The disappearance was instantaneous-magnifying power of the telescope, 75. January 27. By four series of double altitudes of Canopus, near the meridian, observed with the circular reflector, corrected by the horary angles, and refraction, the meridian altitude was determined. 14° 28′ 53,5" By 4 series of similar observations on Sirius. 50 36 54,4 By 10 series of angular distances, observed with the circular reflector, and corrected for refraction, the mutual distance was determined 36° 17′ 19,4". The difference of right ascension in time, of the above stars =16' 59,5". By the distance observed, and the difference of right ascension results the difference of declination. The difference of meridional altitudes difference of declinations, 36° 08′ 00,4" 36 08 00,9 Taking the latitude of the place as stated above 22° 55′ 16′′ and correcting the meridional altitudes observed, from nutation, aberration, and precession, we have the true, or mean declinations of the two stars on 1st January 1808. Canopus. 52° 35′ 34,9′′ 16 27 36,8 Comparing the observations of la Caille on 1750, and supposing the annual precession in longitude=50,1′′ we have the proper motion of Canopus in declination in 58 years-0′ 10,1′′ +1 02,0 Sirius. Mean declination of Sirius, according to the Rev. Nevill Maskelyne on the 1st of January, 1808. Connoisance de temps. By the observation with the circular reflector. 16° 27' 30" 16 27 38,6 16 27 36,8 Astronomical observations made at the city of Havanna. La titude of the place 23° 08′ 30′′. Occultations of stars by the moon, observed with an Achro matic telescope-magnifying power 75. April 5th, 1808. C1 a on the dark limb, apparent time. 374 of Mayer on the dark limb. ditto. ditto, May 2d, 3d, w Lion on the dark limb. The immersions were instantaneous. 11h 53' 34" 9 01 49 10 33 49 Observations made on a lunar eclipse at the city of Havanna, on the 9th of May, 1808-magnifying power of the teleScope 70. The above observations of the lunar eclipse are very exact, excepting the beginning and the end of the eclipse, which are liable to the error of one and a half minute, on account of the strong penumbra. Table of the results of the occultations of the stars by the moon. Longitude of the Plantation W. from Paris-5h 38' 29",7+44",3 Havanna W.. 5 39 03 Solar eclipse of June 16th, 1806, in the city of Havanna. Mean time. With the elements of page 270 of this Volume, I have calculated the conjunction, by the beginning, June 15th. By the first observation of distance By the second. By the third. Conjunction June 15th, Astronomical time. Ditto. in Paris, page 296, June 16th. Havanna west from Paris. By the Solar Eclipse (page 162,) observed in the city of Havanna, and at Lancaster in Pennsylvania. U. S. Havanna west from Lancaster Havanna west from Paris. Oh 24′ 25′′ 5 14 41 5 39 06 Longitude of Havanna, by the observations compared with the new tables published at Paris in 1806. Passage of Venus over the disk of the Sun, June 3d, 1769. Elements from Astronomical tables at Horary motion in O's right ascension. Horary motion of Venus in latitude S. Apparent obliquity of the ecliptic Radius vector of Venus. O's semidiameter. 10h 11' 47" mean time at Paris. 73° 27 18,3 72 03 16 2 34 3 57,40 By a previous calculation of the observations of this passage, I had determined the following elements: Sun's parallax at the mean distance from the earth = = 8'"',62378 Duration of the passage between the interior contacts = 5h 41′ 54′′,5 in mean time. |