Saturday, 14th. First part Strong Gales, and very heavy squalls with Hail and Rain; remainder more moderate but unsettled, sometimes a fresh breeze and Squally, and sometimes little wind. Kept plying in the Straits until ½ past 4 p.m., at which time the Tide had made strong against us, and the wind not abating, bore away, intending to have hauled under Cape St. Diego, but was prevented by the force of the Tide, which carried us past that Cape with surprising rapidity, at the same time caused a very great sea. At 6, the weather being Clear, took 9, or 3 sets of, Observations of the sun and moon in order to find the Longitude of the place, and as they perhaps are the first Observations of this kind that were ever made so near to the Extremity of South America, I have inserted them below just as they were taken, that everybody may judge for themselves.
| Time by the Watch. | Apparent time computed from. | Observed Distance. Sun and Moon's nearest Limb. | Observed Altitude. Sun's lower Limb. | Observed Altitude. Moon's upper Limb. | Correct Altitude. Sun's center. | Correct Altitude. Moon's center. | The Longitude resulting from both sets of Observations. | |
| ʰ ′ ″ 8 27 15 „ 30 30 „ 32 15 |
ʰ ′ ″ | ʰ ′ ″ 71 26 0 71 28 0 71 29 0 |
ʰ ′ ″ 15 36 0 15 11 0 14 56 0 |
ʰ ′ ″ 24 13 0 24 8 0 23 57 0 |
ʰ ′ ″ | ʰ ′ ″ | ʰ ′ ″ | |
| 25 30 00 | — 83 0 | 45 43 0 | 72 18 0 | |||||
| 1st set. | 8 30 0 | 6 12 53 | 71 27 40 | 15 14 20 | 24 6 0 | 15 22 39 | 23 43 0 | 66 7 45 |
| 8 33 50 „ 35 39 „ 37 46 |
71 30 0 31 0 30 30 |
14 43 0 14 25 0 14 10 0 |
23 38 0 23 42 0 23 32 0 |
|||||
| „ 107 15 | 91 30 | 43 18 0 | „ 112 0 | |||||
| 2nd set. | 8 35 45 | 6 18 41 | 71 30 30 | 14 26 0 | 23 37 20 | 14 34 00 | 23 14 0 | 66 19 45 |
| 8 39 10 „ 41 20 „ 43 49 |
71 31 30 32 00 33 00 |
13 56 0 13 40 0 13 18 0 |
23 26 0 23 20 0 23 6 0 |
|||||
| „ 124 19 | 96 30 | 114 0 | 52 0 | |||||
| 3rd set. | 8 41 26 | 6 24 26 | 71 32 10 | 13 38 0 | 23 17 20 | 13 46 0 | 22 55 0 | 66 0 45 |
N.B.—The mean of the three sets is 66° 9′ 25″ , and the mean of Mr. Green's Computations from the same Observations was 66° 14′ 0″, and the mean of his computations and mine will be 66° 11′ 32″, and therefore the Longitude of Cape St. Diego or the N.W. entrance of Strait Le Maire will be 66° 0′ 0″ W. from Greenwich, and its Latitude 54° 39′ South.[1]
Note: The distance of the sun and moon was taken by Mr. Green alone, my Quadrant being out of Order.
- ↑ Modern determination is 54° 40′ S., 65° 8′ W.
