Remarks April 5, 1789 Home Logbook Time Keeper Apr 5, 1789
Revised Jun 30 2021
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Perhaps a period of five months within the Tropics never happened more unfavorable to astronomical observations. The few opportunities however that happened I made the best use of. The result of these observations gave me the situation of Toahroah Harbour as follows. —
Latitude....................................................... 17°..31′..26″ S. Longitude pr. observations of Sun and Stars each side of ☽..... 210..31..37 Et. Longitude pr. Time Keeper on my Arrival........................ 210..24..52 Et. Variation of the Compass....................................... 5..31 Et.
All the observations were made on the Beach 427 fms. from the Morai on the East point of the Harbour and Point Venus lies 2°..20′ Et in longitude from the Observatory.
Point Venus therefore by my observn lies in ..........210°..33′..57″ Et Captn Cook in 1769 places it in ......................210..27..30 In 1777 his last Voyage ..............................210..22..28
So that the difference between us is 6′..27″, for assuredly his
observations in 1769 being all on the spot are to be given the preference.
My Time Keeper from Observations in Matavai Bay gave the
Longitude of Point Venus............................... 210..27..12 Et
I shall only just remark about Lunar observations that I am of opinion, that a good observer with the present improved Instruments of Mr. Ramsdens or others on the same principal, will with 50 sets of distances, at any number of places, determine their relative postions within one Mile of the Truth.
The rise of the Tide on the full and change of the Moon has been from 10 to 9 Inches, and this upon a medium was at one oClock in the afternoon, but
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no regular Tide could I discover at this place, for it was always high water between Noon and about a half past two, remaining two or three hours stationary. And low water in the same manner between 6 and 8½ in the morning. At the quartering of the moon it would Scarce have an Inch rise; but the boisterous & Variable Winds at this Season of the year made everything relative to these observations uncertain. I think therefore my subjoining a Table of the mean of my observations for One Moon, may give a more thorough Idea of this matter.
| Month | Day | ☽ Age | High Water | Perpr rise |
|---|---|---|---|---|
| January | 28th | 4 | 2⋅00 | 10 |
| 29 | 5 | 1⋅45 | 4 | |
| 30 | 6 | 2⋅00 | 6 | |
| February | 1 | 8 | 1⋅30 | 5 |
| 2 | 9 | 1⋅30 | 1½ | |
| 3 | 10 | 1⋅00 | 5 | |
| 5 | 12 | 0⋅30 | 3 | |
| 8 | 15 | 0⋅30 | 7 | |
| 9 | Full | 1⋅00 | 10 | |
| 10 | 2 | 0⋅30 | 11 | |
| 11 | 3 | 0⋅30 | 10 | |
| 12 | 4 | 1⋅00 | 11 | |
| 13 | 5 | 1⋅30 | 10 | |
| 14 | 6 | 1⋅30 | 8½ | |
| 16 | 8 | 1⋅30 | 4 | |
| 18 | 10 | 1⋅00 | 0½ | |
| 19 | 11 | 1⋅30 | 3 | |
| 20 | 12 | 0⋅30 | 4 | |
| 21 | 13 | 0⋅00 | 6 | |
| 22 | 14 | 0⋅00 | 5 | |
| 23 | 16 | 0⋅30 | 9 | |
| 24 | New | 1⋅00 | 9 | |
| 25 | 2 | 0⋅00 | 9 | |
| 26 | 3 | 12⋅00 | 9 | |
| 27 | 4 | 0⋅30 | 7 |
At Matavai I found the Tide subject to the same differences. I however made it High Water at the Change of the Moon at 11h..45′, and it flowed nearly 17 Inches, but at this season, the Winds are Variable both with respect to Strength and direction, with sometimes a heavy Sea on the Reefs and others Smooth water.
Remarks April 5, 1789 Home Logbook Time Keeper Apr 5, 1789