Astronomical Observations Made by Samuel Holland, Esquire, Surveyor-General of Lands for the Northern District of North-America; and Others of His Party. Communicated by the Astronomer Royal

XXXIV. Astronomical Observations made by Samuel Holland, Esquire, Surveyor-General of Lands for the Northern District of North-America; and Others of his Party. Communicated by the Astronomer Royal. Obs. of Lat. March 8, 1769, observed by Samuel Holland, Esquire, at his house, bearing south, $56^\circ$ west from Quebec, distance from the castle of St. Lewis $2\frac{1}{2}$ miles, with Bird's astronomical quadrant, the latitude, viz. Zenith angle of the Sun's upper limb $51^\circ 4'$ Deduct for the Sun's southern declination $4^\circ 34' 3"$ Add the Sun's semi-diameter $46^\circ 29' 29"$ Ditto refraction $16' 9"$ North latitude by observation $46^\circ 47' 20"$ Obs. of Long. March 11, 1769, observed by the same at the same place, with Dollond's refracting telescope, an immersion of the first satellite of Jupiter, at $15$ hours, and $45$ seconds, mean or equal time. Obs. of Lat. March 19, 1769, observed by the same at the same place, with Bird's astronomical quadrant, the latitude, viz. Zenith angle of the Sun's upper limb 46° 45' 2" Deduct for the Sun's southern declination 14° 42" Add the Sun's semi-diameter 46° 30' 20" Ditto refraction 16° 6" North latitude by observation 46° 47' 16" Obs. of Lat. March 20, 1769, observed by the same, at the same place, with the same instrument, the latitude, videlicet, Zenith angle of the Sun's upper limb 46° 21' 16" Add the Sun's northern declination 8° 58' Ditto the Sun's semi-diameter 16° 5½' Ditto the refraction 1° 0" North latitude by observation 46° 47' 19½" N.B. Six more observations of the latitude have been taken. The mean result of the whole is Obs. of Long. April 3, 1769, observed by the same, at the same place, with Dollond's refracting telescope, an immersion of the first satellite of Jupiter, at 15 hours, 10 minutes, and 22 seconds, mean or equal time. Obs. of Long. April 18, 1769, observed by the same, at the same place, with the same instrument, an immersion of the second satellite of Jupiter, at 12 hours, 39 minutes, and 36 seconds, mean or equal time. Obs. of Long. April 19, 1769, observed by the same, at the same place, with the same instrument, an immersion of the first satellite of Jupiter, at 13 hours, 26 minutes, and 27 seconds, mean or equal time. Obs. of Long. May 28, 1769, observed by the same, at the same place, with the same instrument, an emersion of the first satellite of Jupiter, at 14 hours, 2 minutes, and 40 seconds, mean or equal time. Also, observed by the same, at the same place, with the same instrument, a superior conjunction of the fourth satellite of Jupiter, at 11 hours, 14 minutes, and 17 seconds, mean or equal time; and it entirely disappeared at 11 hours, 24 minutes, and 3 seconds, mean or equal time. Obs. of Transi. June 3, 1769, observed, by the same, at the same place, with the same instrument, the Transit of Venus, as follows: at 2 hours, 28 minutes, and 1½ seconds, perceived a luminous point on the lower part of the Sun's limb, by appearance; and, in the same place, 1½ seconds afterwards, the first external contact was formed, which rectified as the clock or time-piece of Graham was 15 seconds too fast at the time of observation (as proved by equal altitudes of the Sun taken with Bird's astronomical quadrant, on the 1st, 2d, 4th, and 5th instant) the equal or mean time of observing the first external contact will be at 2 hours, 27 minutes, and 48 seconds. Mr. St. Germain, of the seminary of Quebec, observed the same contact, at the same instant, with Short's 2 feet reflecting telescope. Clouds, intervening, prevented the observation of the first internal contact: but at 6 o'clock the Planet might be seen with the naked eye on the Sun's disc, through the haziness of the atmosphere. Obs. of Long. June 6, 1769, observed by the same, at the same place, with the same instrument, an emersion of the first satellite of Jupiter, at 10 hours, 26 minutes, and 22 seconds, mean or equal time. Obs. of Lat. January 2, 1768, observed by Ensign George Sproule, of the 59th regiment of foot, on the south point, at the entrance of the basin of Gaspée, with Hadley's quadrant, and an artificial horizon, the latitude, viz. Double angle of the meridian } 36° 38' 0" altitude of the Sun's center Apparent altitude of the Sun's center 18° 19' 0" Refraction . . . . . . . . . . . 2° 41' True altitude of the Sun's center 18° 16' 19" 90° 0' 0" Sun's zenith distance . . . . 71° 43' 41" Sun's declination reduced to the } 22° 56' 10" meridian of Gaspée North latitude by observation 48° 47' 31" Obs. of Lat. May 9, 1768, observed by the same, at the same place, with the same instrument, and an artificial horizon, the latitude, videlicet, Double angle of the Sun's lower } 117° 6' 0" limb, meridian altitude Add for adjusting the quadrant, error to the right, } 2° 10' 117° 8' 10" Apparent altitude of the Sun's } 58° 34' 5" lower limb Add the Sun's semi-diameter 15° 53' Apparent altitude of the Sun's center 58° 49' 58" Deduct for Refraction . . . . . . . . . . . 53' True altitude of the Sun's center 58° 49' 25" 90° 0' 0" Sun's zenith distance . . . . 31° 10' 35" Add the Sun's declination, reduced } 17° 36' 56" to the meridian of Gaspée North latitude by observation 48° 47' 31" Obs. May 15, 1768, observed by the same, at the same place, with the same instrument, and an artificial horizon, the latitude, viz. Double angle of the Sun's upper limb, meridian altitude } 121° 10' 0" Subtract for adjusting the quadrant error to the left } 35 121° 9' 25" Apparent altitude of the Sun's upper limb } 60° 34' 42" Subtract the Sun's semi-diameter } 15° 51' Apparent altitude of the Sun's center } 60° 18' 51" Subtract for refraction } 31 True altitude of the Sun's center } 60° 18' 20" 90° 0' 0" Sun's zenith distance } 29° 41' 40" Add Sun's declination reduced to the meridian of Gaspée } 19° 5' 50" North latitude by observation } 48° 47' 30" N. B. There were 12 more observations made of the latitude, by the same person; but these are judged sufficient to shew his manner of operation: but the result of the whole 15 make the place of observation 48° 47' 32" north latitude. January 29, 1768, observed by the same person, at the same place, with Short's two feet reflecting telescope, an immersion of the first satellite of Jupiter, at 14 hours, 11 minutes, and 3 seconds, mean or equal time. March 15, 1768, observed by the same person, at the same place, with the same instrument, an immersion of the first satellite of Jupiter, at 14 hours. hours, 29 minutes, and 38 seconds, equal or mean time. Obs. of Long. March 16, 1768, observed by the same, at the same place, with the same instrument, an immersion of the second satellite of Jupiter, at 12 hours, 7 minutes, and 16 seconds, equal or mean time. Obs. of Long. March 16, 1768, observed an immersion of the third satellite of Jupiter, at 13 hours, 38 minutes, and 18 seconds, equal or mean time; by the same person, with the same instrument, at the same place. Obs. of Long. April 9, 1768, observed by the same person, at the same place, with the same instrument, an emergence of the first satellite of Jupiter, at 11 hours, 19 minutes, and 24 seconds, equal or mean time. Obs. of Long. April 10, 1768, observed by the same person, at the same place, with the same instrument, an emergence of the second satellite of Jupiter, at 11 hours, 38 minutes, and 45 seconds, equal or mean time. Obs. of Long. April 25, 1768, observed by the same person, at the same place, with the same instrument, an emergence of the first satellite of Jupiter, at 9 hours, and 37 minutes, equal or mean time. N. B. This observation is thought to be as exact as possible, the satellite emerging totally in an instant, and the clock being truly regulated by a number of single and corresponding altitudes. Obs. of Long. May 9, 1768, observed by the same person, at the same place, with the same instrument, an emergence of the first satellite of Jupiter, at 13 hours, 26 minutes, and 47 seconds, equal or mean time. Obs. of Long. May 12, 1768, observed by the same person, at the same place, with the same instrument, an emergence of the second satellite of Jupiter, at 11 hours, 11 minutes, and 34 seconds, equal or mean time. Samuel Holland.