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Re: Lewis and Clark. was: sextant practice and time keepers
From: George Huxtable
Date: 2010 Sep 21, 18:05 +0100
From: George Huxtable
Date: 2010 Sep 21, 18:05 +0100
Bravo! I wondered if Antoine could be tempted by my words... If he goes a bit up the page, he will find- =============== 2 Dec 1803. (Moulton pages 119-122 ) During a few days' pause, 3 miles West of [old] Kaskaskia. L&C recorded several observations. Where were they? Nowadays, we have a distinct advantage over L&C, in that we know, within a mile or two, where their camp had been set up at Kaskaskia since 28 Nov., using modern mapping. From the website associated with Harlan and Denny's "Atlas of Lewis and Clark in Missouri", this is determined as N37.985 (37deg 59.1'), W89.953 (89deg 57.2'). See section 1.2. ====================== After correcting some equal-altitude observations, made for another purpose, we can find- "These revised timings result in a deduced latitude of 37° 58.6', which is very close to our estimated position from the atlas of 37° 59.1' , within 0.5'." However. Lewis thought otherwise- "Lewis states, at the top of page 121- "observed meridian Altd. of Sun's Lower Limb, with my Octant & artificial horizan, found it 58° 38' Error of Octant 2° additive. Latd, from the preceding observation with Octant- 38° 20' 57". Lewis does not explain how he arrives at that result." As for his longitude, I think it's fair to say that Lewis had little idea where he was. George. contact George Huxtable, at george@hux.me.uk or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. ----- Original Message ----- From: "Antoine Couette"To: Sent: Tuesday, September 21, 2010 5:30 PM Subject: [NavList] Re: Lewis and Clark. was: sextant practice and time keepers Dear George, For the Lunar distance observations, night of 2-3 Dec, 1803, you indicated : "Those confusions relate to ordinary altitude observations, but things get much worse when we reach the attempts at a lunar, at Kaskaskia, on the night of 2-3 December, 1803. Try as I might, I am quite unable to unravel the observations to make sense of them. If anyone else can arrive at any understanding, I would be most pleased to hear about it. Details are all there on the website, if you follow the journey to that date." I wish to give it a try : what observer's coordinates should I (best) use to re-work these Lunars ? Thank you and Best Regards Kermit ---------------------------------------------------------------- NavList message boards and member settings: www.fer3.com/NavList Members may optionally receive posts by email. To cancel email delivery, send a message to NoMail[at]fer3.com ----------------------------------------------------------------